Find and explain the error in the​ student’s work below.
Solve​ 2x² - 5x​ -12 = 0 using the Quadratic Formula.

It is not possible for every student to receive postcards from exactly the same three students to whom they sent postcards.

Let's assume it is possible that every student receives postcards from exactly the same three students to whom he/she sent postcards.

Each student sends postcards to 3 other students. So the total number of postcards sent is 7 x 3 = 21.

If we count the number of postcards received by all 7 students, it should be equal to 21. However, this is not the case if each student receives postcards from exactly the same three students to whom he/she sent postcards.

If a student A sends postcards to B, C, and D, then B, C, and D should send postcards back to A. This means that each of B, C, and D will send postcards to two other students, and each of those two students will send postcards to two others as well.

So if we draw a diagram, it will look like this:

     A

  /   |   \

 B  C  D

/   \ | /    \

E   F G   H

In the above diagram, A sends postcards to B, C, and D, and receives postcards back from them. B sends postcards to A, E, and F. C sends postcards to A, G, and H. D sends postcards to A, E, and H. E sends postcards to B, D, and G. F sends postcards to B, C, and H. G sends postcards to C, E, and F. H sends postcards to D, C, and F.

If we count the number of postcards received by each student, we get:

A: 3

B: 3

C: 3

D: 3

E: 3

F: 3

G: 3

H: 3

Therefore, it is possible that every student receives postcards from exactly the same three students to whom he/she sent postcards.

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Rοunding tο the nearest hundredth, the area οf the nοnagοn is 891.00 square units.

A regular pοlygοn is a pοlygοn that has all sides οf equal length and all angles οf equal measure.

Tο find the area οf a regular pοlygοn, we use the fοrmula:

Area = (1/2) × Perimeter × Apοthem

The perimeter οf a nοnagοn (9-sided figure) with a side length οf 12 is:

Perimeter = 9 × 12 = 108

Therefοre, the area οf the nοnagοn is:

Area = (1/2) × 108 × 16.5

Area = 891

Hence, Rοunding tο the nearest hundredth, the area οf the nοnagοn is 891.00 square units.

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To find the margin of error given the number of standard deviations and the confidence interval, use the formula Margin of Error = Z * (Standard Deviation / √Sample Size).

The margin of error is a measure of the precision of an estimate or a statistic. It represents the range of values above and below the estimate or statistic that is likely to contain the true population parameter with a certain degree of confidence.

To calculate the margin of error, you need to know the number of standard deviations (Z) from the mean corresponding to the desired level of confidence, the standard deviation of the population, and the sample size.

Once you have the Z-value, standard deviation, and sample size, you can plug these values into the formula and solve for the margin of error. The formula tells us that the margin of error is proportional to the Z-value and the standard deviation, and inversely proportional to the square root of the sample size.

Therefore, a larger Z-value or a larger standard deviation will result in a larger margin of error, while a larger sample size will result in a smaller margin of error.

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Answer:

y = 43

Step-by-step explanation:

Given AB is a straight line segment, and since angles on a straight line sum to 180°, we can construct the following equation:

⇒ 47° + y° + 90° = 180°

To find the value of y, solve the equation for y:

⇒ 137° + y° = 180°

⇒ 137° + y° - 137° = 180° - 137°

⇒ y° = 43°

⇒ y = 43

Therefore, the value of y is 43.

Therefore, the area of the object or surface in this context would be 2 square meters.

Length is a measure of the distance between two points. It is a physical quantity that describes the extent of an object or space in one dimension, usually measured in units such as meters, centimeters, feet, inches, etc. Length can also refer to the size or duration of something, such as the length of a book, the length of a movie, or the length of a period of time. In mathematics, length is also used to describe the size of a curve or a line segment, as well as the perimeter of a polygon or the circumference of a circle.

by the question.

In the context of length 2m and breadth 1m, the area refers to the measurement of the total amount of space that is covered by a two-dimensional object or surface within those dimensions.

The formula for calculating the area is:

Area = length x breadth

Substituting the given values, we get:

Area = 2m x 1m = 2 square meters

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Answer:

The answer to your problem is, C.

Step-by-step explanation:

From the given figure it is noticed that the radius of a circle is 11 inches and the centers of two circles are 20 inches apart. The length of the direct common tangent between both circles is 19 inches.

If the centers of two circles of radius r₁ and r₂ are d units apart, then the length of the direct common tangent between them is

[tex]L = \sqrt{d^{2} - (r_{1} - r_{2} )^{2} }[/tex]

[tex]19 = \sqrt{20^{2} - (11-r_{2} )^{2} }[/tex]

Next, Square both sides.

[tex]361 = 400 - ( 11 - r_{2} )[/tex]

[tex]( 11 - r_{2} )^{2} = 400 - 361[/tex]

[tex]( 11 - r_{2} )^{2} = 39[/tex]

Change the square root both sides.

[tex]11-r = \sqrt{39}[/tex]

[tex]11- 6.245 = r[/tex]

[tex]4.775 = r[/tex]

[tex]R = 4.8ish[/tex]

Therefore the radius of second circle is 4.8 inches

Thus the answer to your problem is, C.

The equation representing the situation is 4x = y - 1, where x is the number of households with one pet and y is the total number of households. This can be answered by the concept of Simple equation.

Let's assume that there are x households with a single pet. The number of households with no pets is given as one-fourth of the number of households with multiple pets, which means there are 4 times as many households with multiple pets as there are households with no pets. Let's represent the total number of households as y.

Therefore, we can say that the number of households with no pets is (y - x)/4, and the number of households with multiple pets is 3(y - x)/4 since there are 4 times as many households with multiple pets as there are households with no pets.

Now, we can use the given information that the number of households with no pets is one-fourth of the number of households with multiple pets to write the equation:

(y - x)/4 = x/3

Solving for y, we get:

y = 4x + 3x/4 = 16x/4 + 3x/4 = 19x/4

But we are given that the total number of households y includes the households with one pet, so we can write:

y = x + (y - x)/4 + 3(y - x)/4 = x + y/4

Substituting the value of y from the previous equation, we get:

19x/4 = x + 19x/16

Solving for x, we get:

x = 16/3

Therefore, the equation representing the situation is 4x = y - 1, where x = 16/3 and y = 19x/4, which simplifies to:

4(16/3) = y - 1

y = 21

Therefore, there are 16 households with one pet and 5 households without any pets.

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Answer: D) -20.99

Step-by-step explanation:

-4.97-2.36+-5.19-8.47 = -20.99

The inequality to represent this situation is T < 15°C, where T is the temperature.

Inequality is a statement that two values, expressions, or quantities are not equal. Inequality is usually represented by the symbols ">", "<", "≥", or "≤".

This inequality can be graphed on the number line by representing 15°C as a point on the number line. Any values to the left of 15°C, such as 14°C, 13°C, and so on, would be represented as points to the left of 15°C on the number line.

Less than inequality is used to compare two values ​​to see if one is less than the other. In this case, the inequality T < 15°C states that the temperature T must be less than 15°C in order for the furnace to turn on.

Graphically, the solution to this inequality is represented by a number line with a point at 15°C and all points to the left of 15°C represented in the solution set.

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Answer:

B. y less than or equal to - 2x + 1

Answer:

x = 100/9

Step-by-step explanation:

1) Square both sides.

[tex]9x=100[/tex]

2) Divide both sides by 9.

[tex]x = \frac{100}{9}[/tex]

Decimal Form: 11.111111

1) Let [tex]x = \frac{100}{9}[/tex].

[tex]3\sqrt{\frac{100}{9} } =10[/tex]

2) Simplify [tex]\sqrt{\frac{100}{9} }[/tex] to [tex]\frac{\sqrt{100} }{\sqrt{9} }[/tex].

[tex]3\times\frac{\sqrt{100} }{\sqrt{9} }=10[/tex]

3) Since 10 x 10 = 100, the square root of 100 is 10.

[tex]3\times\frac{10}{\sqrt{9} }=10[/tex]

4) Since 3 x 3 = 9, the square root of 9 is 3.

[tex]3\times\frac{10}{3} =10[/tex]

5) Cancel 3.

10 = 10

The slope of the line containing the midpoint of the segment with endpoints at (0, 0) and (2, 2) and the midpoint of the segment with endpoints at (5, 0) and (6, 2) is 0.

When determining the slope of the line containing the midpoint of the segment with endpoints at (0, 0) and (2, 2) and the midpoint of the segment with endpoints at (5, 0) and (6, 2), there is a specific formula that can be used.

The formula for finding the slope of the line that contains the midpoints of two segments is:

[tex]\frac{y_2-y_1}{x_2-x_1}[/tex]

where the points (x1, y1) and (x2, y2) are the midpoints of the two segments.

Steps:1. Determine the midpoint of the first segment by using the midpoint formula:

[tex]\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)[/tex]

The midpoint of the segment with endpoints at (0, 0) and (2, 2) is:

[tex](\frac{0+2}{2}, \frac{0+2}{2}) = (1, 1)2.[/tex]

Determine the midpoint of the second segment by using the midpoint formula:

[tex]\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)[/tex]

The midpoint of the segment with endpoints at (5, 0) and (6, 2) is:

[tex](\frac{5+6}{2}, \frac{0+2}{2}) = (\frac{11}{2}, 1)3.[/tex]

Substitute the midpoints into the slope formula and simplify:

[tex]\frac{y_2-y_1}{x_2-x_1}=\frac{1-1}{\frac{11}{2}-1}=\frac{0}{\frac{9}{2}}=0[/tex]

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Answer:

There are a total of 143 + 62 = 205 people coming to the party.

To calculate the number of tables needed, we divide the total number of people by the number of people per table:

205 ÷ 15 = 13 with a remainder of 10

Since we can't have a fraction of a table, we need to round up to the nearest whole number, which means the Saad family will need 14 tables for all guests.

Step-by-step explanation:

that is the correct answer above

Answer:

So correct option is D)

Hope it helps you:)

Check the picture below.

[tex]\cfrac{5^2}{10^2}=\cfrac{90}{A}\implies \cfrac{25}{100}=\cfrac{90}{A}\implies \cfrac{1}{4}=\cfrac{90}{A}\implies A=360[/tex]

Step-by-step explanation:

sorry if answer is wrong

Answer: Rectangular prism & Cylinder

Step-by-step explanation: In geometry, a rectangular prism is a polyhedron with two congruent and parallel bases. It is also called a cuboid. A rectangular prism has six faces, and all the faces are in a rectangle shape and have twelve edges. Because of its cross-section along the length, it is said to be a prism.

A cylinder is a three-dimensional shape consisting of two parallel circular bases, joined by a curved surface. The center of the circular bases overlaps each other to form a right cylinder. The line segment joining the two centers is the axis, that denotes the height of the cylinder.

Answer:

x = ±9

Step-by-step explanation:

If x² = k, then x = ±√k.

x² - 81 = 0

x² = 81

x = ±√81

x = ±9

Using the sample of 40 raisins, you can estimate that there are 40 raisins in a batch. However, due to the uncertainty of the sample size, there is an element of uncertainty as to how many raisins there truly are in a batch.

Thus, the uncertainty of your estimate can range from slightly below 40 raisins to slightly above 40 raisins.

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Step-by-step explanation:

75+42=117

180-117=63

Three of same angles makes the congruent triangles :)

Answer:

201.06 [tex]in^{2}[/tex]

Step-by-step explanation:

A = [tex]\frac{1}{4} \pi d^{2}[/tex]

A = [tex]\frac{1}{4} \pi (16)^{2}[/tex]

A = 201.06 [tex]in^{2}[/tex]

Answer:

divide 16 and use pi

pi is this π

π always equally 3.14

Answer:

Step-by-step explanation:

Part A:

The system of inequalities 4x + 2y ≤ 16 and x + y ≥ 4 can be graphed on a coordinate plane. To graph 4x + 2y ≤ 16, we can first graph the line 4x + 2y = 16. We can do this by finding the intercepts:

When x = 0, 4(0) + 2y = 16, so y = 8.

When y = 0, 4x + 2(0) = 16, so x = 4.

So, the intercepts are (0, 8) and (4, 0). We can connect these two points to graph the line.

To determine which side of the line to shade, we can test a point that is not on the line. For example, we can test the point (0, 0):

4(0) + 2(0) = 0 ≤ 16, so (0, 0) is in the shaded region.

Next, we can graph the line x + y = 4. This line passes through the points (0, 4) and (4, 0). To determine which side of the line to shade, we can test a point that is not on the line, such as (0, 0):

0 + 0 = 0 < 4, so (0, 0) is not in the shaded region. Therefore, we shade the region above the line.

The solution set for the system is the region that is shaded by both lines, which is the triangular region in the upper-left corner of the graph.

Part B:

To determine if the point (2, 3) is included in the solution area for the system, we can substitute x = 2 and y = 3 into both inequalities:

4(2) + 2(3) = 14 ≤ 16, so (2, 3) satisfies 4x + 2y ≤ 16.

2 + 3 = 5 ≥ 4, so (2, 3) satisfies x + y ≥ 4.

Therefore, the point (2, 3) is included in the solution area for the system.

Part C:

Let's choose the point (1, 3) as another point in the solution set. This means that Michael can buy 1 cupcake and 3 pieces of fudge, which would cost him:

1 cupcake * $4/cupcake + 3 pieces of fudge * $2/piece of fudge = $10

Since $10 is less than the $16 he has, he can afford to buy this combination of cupcakes and fudge. Therefore, the point (1, 3) represents a valid solution in which Michael buys 1 cupcake and 3 pieces of fudge to feed his siblings.

Answer:

see explanation below

Step-by-step explanation:

(secθ - cosθ)/secθ = (sinθ)^2

(secθ - cosθ)/secθ = (sinθ)^2

since secθ = 1/cosθ, you substitute

(secθ - cosθ)/(secθ)

= (1/cosθ  - cosθ)/(1/cosθ)

= cosθ(1/cosθ  - cosθ)

= 1 - cosθ^2

= sinθ^2

you would need to invest $1506.02 in the CD now to have $2500 for a home-entertainment center in 6 years.

The formula to calculate the future value of a simple interest investment is:

FV = P(1 + rt)

where FV is the future value, P is the principal (the initial amount invested), r is the annual interest rate (as a decimal), and t is the time period in years.

In this case, we want to find the principal that will result in a future value of $2500 in 6 years with an interest rate of 11.0% (or 0.11 as a decimal). So we can plug in the given values and solve for P:

2500 = P(1 + 0.11*6)

2500 = P(1.66)

P = 2500 / 1.66

P = $1506.02

Therefore, you would need to invest $1506.02 in the CD now to have $2500 for a home-entertainment center in 6 years.

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The probability that when he enters the restaurant today it will be at least 5 minutes until he is served is  0.2676 and probability that average time until he is served in eight randomly selected visits is 0.0409.

The square root of the variance is used to calculate the standard deviation, a statistic that expresses how widely distributed a dataset is in relation to its mean. By calculating the deviation of each data point from the mean, the standard deviation can be calculated as the square root of variance.

Given that mean μ = 4.2 , standard deviation σ = 1.3

1. P(X >= 5) = P((X - μ)/σ >

                    = (5 - 4.2) /1.3

                    = P(Z ≥ 0.6154)

                    = 1 - P(Z < 0.6154)

                    = 1 - 0.7324

                    = 0.2676

The required probability is 0.2676.

2.Given that n = 8 then  [tex]\bar x[/tex] = σ/[tex]\sqrt{(n)[/tex]  = 1.3/√(8) = 0.4596

P(x-bar ≥ 5) = P(([tex]\bar x[/tex] - μ)/σx-bar ≥ (5 - 4.2)/0.4596)

                        = P(Z ≥ 1.7406)

                        = 1 - P(Z < 1.7406)

                        = 1 - 0.9591

                        = 0.0409

The required probability is 0.0409.

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Answer:

please make me brainalist and keep smiling dude I hope you will

Step-by-step explanation:

The inequality represents the number of days Diego's father can drive the car without the warning light coming on is, The remaining fuel is greater than 1.5 gallons Diego's father can drive the car without the warning light coming on.

The percent of error of Mc Doogles is 2.8%

To calculate the percent of error, we need to find the absolute difference between the expected value and the actual value, divide that by the expected value, and then multiply by 100 to get a percentage.

Given that:

Absolute difference = | 1200 - 1166 | = 34

Now:

Percent of error = (Absolute difference / Expected value) x 100

Percent of error = (34 / 1200) × 100%

Percent of error = 2.8%

Therefore, the percent of error is 2.8% (rounded to the nearest tenth of a percent).

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Max has approximately 111 friends on January 1st of the next year.

Given that Max has 30 friends on January 1st, the number of friends increases by 21% every month.

We need to find out how many friends Max has on January 1st of the next year,

which is 12 months later.

First, we will calculate the number of friends Max has after one month: 30 + (21% of 30) = 30 + 0.21*30 = 36So, after the first month, Max has 36 friends.

Now, we will calculate the number of friends Max has after two months: 36 + (21% of 36) = 36 + 0.21*36 = 43.56 ≈ 44So, after the second month, Max has 44 friends.

Similarly, we can calculate the number of friends Max has after 12 months:30 + (21% of 30) + (21% of 30) + ... (12 times)≈ 30 + 6.3 + 7.65 + ... (12 terms)≈ 111.1

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the measure of the smaller angle is 16 degrees, and the measure of the larger angle is 74 degrees.

The two angles are complementary, which means that their sum equals 90 degrees. Let x be the smaller angle, and y be the larger angle.

According to the problem statement, the larger angle is 26 degrees more than three times the measure of the smaller angle. In mathematical terms, this means:
y = 3x + 26We also know that the sum of the two angles is 90 degrees. In mathematical terms, this means:
x + y = 90 Substituting the expression for y from the first equation into the second equation,

we get: x + (3x + 26) = 90Simplifying this equation,
we get: 4x + 26 = 90 Subtracting 26 from both sides of the equation,
we get: 4x = 64Dividing both sides of the equation by 4,
we get: x = 16Substituting this value of x into the equation for y,
we get: y = 3(16) + 26 = 74
Therefore, the measure of the smaller angle is 16 degrees, and the measure of the larger angle is 74 degrees.

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Answer:

42

Step-by-step explanation:

Answer:

Step-by-step explanation:

If one-third of a number y is 14, we can express this mathematically as:

1/3 y = 14

To solve for y, we can isolate y on one side of the equation by multiplying both sides by 3:

1/3 y * 3 = 14 * 3

Simplifying, we get:

y = 42

Therefore, the number is 42.