Mark is solving the following systems Step 1: He multiplies equation (1) by 7 and adds it to equation (3). Step 2: He multiplies equation (3) by 2 and adds it to equation (2). Which statement explains Mark’s mistake? He added equation (3) instead of equation (2) in step 1. He did not multiply equation (3) by the same number as equation (1). He did not eliminate the same variables in steps 1 and 2. He added equation the equations in step instead of subtracting them.

Answer:

[tex] y'' =12x^2 -72=0[/tex]

And solving we got:

[tex] x=\pm \sqrt{\frac{72}{12}} =\pm \sqrt{6}[/tex]

We can find the sings of the second derivate on the following intervals:

[tex] (-\infty<x< -\sqrt{6}) , y'' = +[/tex] Concave up

[tex]x=-\sqrt{6}, y =-180[/tex] inflection point

[tex] (-\sqrt{6} <x< \sqrt{6}), y'' =-[/tex] Concave down

[tex]x=\sqrt{6}, y=-180[/tex] inflection point

[tex] (\sqrt{6}<x< \infty) , y'' = +[/tex] Concave up

Step-by-step explanation:

For this case we have the following function:

[tex] y= x^4 -36x^2[/tex]

We can find the first derivate and we got:

[tex] y' = 4x^3 -72x[/tex]

In order to find the concavity we can find the second derivate and we got:

[tex] y'' = 12x^2 -72[/tex]

We can set up this derivate equal to 0 and we got:

[tex] y'' =12x^2 -72=0[/tex]

And solving we got:

[tex] x=\pm \sqrt{\frac{72}{12}} =\pm \sqrt{6}[/tex]

We can find the sings of the second derivate on the following intervals:

[tex] (-\infty<x< -\sqrt{6}) , y'' = +[/tex] Concave up

[tex]x=-\sqrt{6}, y =-180[/tex] inflection point

[tex] (-\sqrt{6} <x< \sqrt{6}), y'' =-[/tex] Concave down

[tex]x=\sqrt{6}, y=-180[/tex] inflection point

[tex] (\sqrt{6}<x< \infty) , y'' = +[/tex] Concave up

Answer:

The answer is option B

Step-by-step explanation:

To find cos 45° we must first find the adjacent and the hypotenuse

Let the adjacent be x

Let the hypotenuse be h

To find the adjacent we use tan

tan ∅ = opposite / adjacent

From the question

the opposite is 9

So we have

tan 45 = 9 / x

x tan 45 = 9

but tan 45 = 1

x = 9

Since we have the adjacent we use Pythagoras theorem to find the hypotenuse

That's

h² = 9² + 9²

h² = 81 + 81

h² = 162

h = √162

h = 9√2

Now use the formula for cosine

cos∅ = adjacent / hypotenuse

The adjacent is 9

The hypotenuse is 9√2

So we have

cos 45 = 9/9√2

We have the final answer as

Hope this helps you

Answer:

[tex]\boxed{m = -2}[/tex]

Step-by-step explanation:

[tex]0 = 4+4(m+1)[/tex]

Resolving Parenthesis

[tex]0 = 4+4m + 4[/tex]

[tex]0 = 4m+8[/tex]

Subtracting 8 to both sides

[tex]-8 = 4m[/tex]

[tex]4m = -8[/tex]

Dividing both sides by 4

m = -8/4

m = -2

Step-by-step explanation:

4+4m+4= 0

4m+8=0

4m=-8

m= -8/4=-2

Answer:

A.

Step-by-step explanation:

40x is the number of lawns he can do, less the time to do his grandparents time (added to other law time) and he has 660 mins of less to complete them.

Answer:

a. 40x + 110 ≤ 660

Step-by-step explanation:

Answer:

It does not have an answer as 3x != 3x + 13 or not equalivalent

Step-by-step explanation:

Answer:

no solution

Step-by-step explanation:

3x+8=9+3x-14

Combine like terms

3x+8 = 3x -5

Subtract 3x from each side

8 = -5

This is never true so there is no solution

Answer:

A =625 ft^2

Step-by-step explanation:

The perimeter of a square is

P = 4s where s is the side length

100 =4s

Divide each side by 4

100/4 = 4s/4

25 = s

A = s^2 for a square

A = 25^2

A =625

Answer:

1. Sometimes

2. Sometimes

3. Always

4. Sometimes

Step-by-step explanation:

1. Quadratic function : in which maximum power of [tex]x[/tex] is two.

The roots of quadratic function can be either equal or different.

For example:

So, sometimes is the correct answer.

2. Cubic function has atleast 1 real root.

Cubic function has maximum power of [tex]x[/tex] as 3.

If the coefficients are real numbers then atleast 1 real root.

If the coefficients are imaginary in nature, then this is not true.

For example:

Cubic equation [tex]x^3 +i = 0[/tex] does not have any real root.

Cubic equation [tex]x^3 +1 = 0[/tex] has a real root x = -1.

So, it is sometimes true.

3. A function with degree 5 i.e. maximum power of [tex]x[/tex] as 5 will have 5 roots.

It is always true that a function will have number of roots equal to its degree.

4. Quadratic function can have only 1 complex solution.

Two complex solutions are also possible for a quadratic function.

For example:

[tex]x^{2} +1=0[/tex] will have two imaginary roots: [tex]x=i, -i[/tex]

It is also possible to have 1 complex solution,

For example:

[tex](x-1)(x-i) = 0[/tex] will have one complex root and one real root.

So, the statement is sometimes true.

Answer:

MY ANSWER IS CORRECT IN PLATO!!!

1. Sometimes

2. Always

3. Always

4. Never

Step-by-step explanation:

1. A quadratic function has 2 distinct roots SOMETIMES

2. A cubic Function has at least 1 root ALWAYS

3. A function with a degree of 5 has 5 roots ALWAYS

4. A quadratic function can have only 1 complex solution NEVER

I JUST GOT 100% on the quiz in PLATO

Answer:

[tex]Circumference = 21.99 \ m[/tex]

Step-by-step explanation:

Circumference = [tex]\pi d[/tex]

Given that d = 7 m

[tex]Circumference = (3.14)(7)\\[/tex]

[tex]Circumference = 21.99 \ m[/tex]

Answer:

[tex]\boxed{21.98 \: \mathrm{meters}}[/tex]

Step-by-step explanation:

Apply formula for circumference of a circle.

[tex]C=\pi d[/tex]

[tex]d:diameter[/tex]

Take [tex]\pi =3.14[/tex]

Plug [tex]d=7[/tex]

[tex]C=3.14 \times 7[/tex]

[tex]C= 21.98[/tex]

Answer:

Option D.

Step-by-step explanation:

The vertex form of an absolute function is

[tex]y=a|x-h|+k[/tex]

where, a is a constant, (h,k) is vertex.

It is given that, vertex of an absolute function is (2,3). So, h=2 and k=3.

[tex]y=a|x-2|+3[/tex]   ...(1)

It crosses the x-axis at (5,0). So put x=5 and y=0 to find the value of a.

[tex]0=a|5-2|+3[/tex]

[tex]-3=3a[/tex]

[tex]-1=a[/tex]

Put a=-1 in (1).

[tex]y=(-1)|x-2|+3[/tex]

[tex]y=-|x-2|+3[/tex]

Now, put y=0, to find the equation for this absolute value function when y=0.

[tex]0=-|x-2|+3[/tex]

Therefore, the correct option is D.

Answer:

I got this question on my test and I answered D cause if you look up the graph it matches the question

Step-by-step explanation:

D 0=−|x−2|+3

Answer:  4:9

Step-by-step explanation:

The complete question is provide in the attachment below.

Given, Number of females = 125

Number of males = 100

Total people = 120+100=225

Now, the ratio of males to the total number of people present = [tex]\dfrac{\text{Total number of males}}{\text{Total people}}[/tex]

[tex]=\dfrac{100}{225}[/tex]

Divide numerator and denominator by 25 , we get

Ratio of males to the total number of people present =[tex]\dfrac{4}{9}[/tex]

Hence, the ratio of males to the total number of people present =  4:9

Answer:

31 m

Step-by-step explanation:

v=l*w*h since it is a cube then all sides (a) are equal:

v=(a*a*a)=a^3

v1+v2=1331 for the first two boxes(

a³+a³=∛1331

l=w=h=11*2=22

v=729 ( for the second cube)

a=∛729=9

9+22=31 m

Answer:

The p-value is 0.809.

Step-by-step explanation:

In this case we need to perform a significance test for the standard deviation.

The hypothesis is defined as follows:

H₀: σ₀ = 4 vs. Hₐ: σ₀ ≤ 4

The information provided is:

n = 9

s = 3

Compute the Chi-square test statistic as follows:

[tex]\chi^{2}=\frac{(n-1)s^{2}}{\sigma_{0}^{2}}[/tex]

     [tex]=\frac{(9-1)\cdot (3)^{2}}{(4)^{2}}\\\\=\frac{8\times 9}{16}\\\\=4.5[/tex]

The test statistic value is 4.5.

The degrees of freedom is:

df = n - 1

   = 9 - 1

   = 8

Compute the p-value as follows:

[tex]p-value=P(\chi^{2}_{9}>4.5)=0.809[/tex]

*Use a Chi-square table.

Thus, the p-value is 0.809.

Answer:

Step-by-step explanation:

y = -5x² - 4x + 1 is a quadratic and thus is defined on the domain "all real numbers."  Because of the negative sign in front of the x^2 term, we know that this parabolic curve opens downward.  The x-coordinate of the vertex is x = -b/[2a], which in this case is x = 4/[2*-5], or -4/10, or -2/5.  Using synthetic division to determine the y-coordinate of the vertex, we get vertex (-2/5, 9/5).  9/5 is the maximum y value.  The range is (-infinity, 9/5].

Answer: A, (0, -3)

Step-by-step explanation:

Inequalities, once graphed, take the form of the image you attached:

Linear inequalities are straight lines, sometimes dotted and sometimes solid, with shading on one side of the line.

Any point in the shading is a correct solution to the inequality.

In this case, the line is solid, so any point on the line is a solution to the inequality.

Looking at answer choice A: (0, -3), it lies on the line as the y-intercept.

The correct choice is A.

Answer: 63°

Step-by-step explanation:

Since BD is the diameter, then arc BCD = 180°

Given that arc BC = 54°, then arc CD = 180° - 54° = 126°

∠DBC is an intercepted angle -> DBC = half of arc CD

[tex]\angle DBC=\bigg(\dfrac{1}{2}\bigg)126^o\quad =\large\boxed{63^o}[/tex]

Answer:

63

Step-by-step explanation:

Answer:

EB = 9

Step-by-step explanation:

CD = AB

The line with the value of five that also forms a right angle with EB is a perpendicular bisector to AB.

So the value of EB is half of AB (AB is equal to CD).

18/2 = 9

Answer: c(x) = $50*x + $24

Step-by-step explanation:

First, this situation can be modeled with a linear equation like:

c(x) = s*x + b

where c is the cost, s is the slope, x is the number of cubic yards of mulch bought, and b is the y-intercept ( a constant that no depends on the number x)

Then we know that:

The company charges $50 per cubic yard, so the slope is $50

A delivery charge of $24, this delivery charge does not depend on x, so this is the y-intercept.

Then our equation is:

c(x) = $50*x + $24

This is:

"The cost of buying x cubic yards of mulch"

Answer:

11 + Mai's Score = 59

Step-by-step explanation:

You need to add 11 and Mai's score together to get 59, so with the values given we can make the equation 11 + Mai's Score = 59.

*depending on the question, Mai's score may need to be said as a letter variable, so:

If m = mai's score,

11 + m = 59

I hope this helped! :)

Answer: 430

Step-by-step explanation:

An average of 5 scores can be found via: (the sum of the scores)*5.  Thus, simply multiply 86*5 to get that the sum of his scores is 430

Hope it helps <3

Answer:

Taylor sold 42 pizzas

Step-by-step explanation:

Make a system of equations where t represents the number of pizzas Taylor sold and j represents the number that Jeff sold:

t + j = 126

j = 2t

We can solve this system by substitution, since we can substitute 2t as j.

t + j = 126

t + 2t = 126

3t = 126

t = 42

Taylor sold 42 pizzas.

Answer:

Step-by-step explanation:

Let x represent the number of pizzas that Tailor sold.

Let y represent the number of pizzas that Jeff sold.

Together they have sold a total of 126 pizzas. This means that

x + y = 126- - - - - - - - -1

Taylor has sold half as many

pizzas as Jeff. This means that

x = 1/2 × y = y/2

Substituting x = y/2 into equation 1, it becomes

y/2 + y = 126

Multiplying both sides of the equation by 2, it becomes

y + 2y = 252

3y = 252

y = 252/3

y = 84

x = y/2 = 84/2

x = 42

Taylor sold 42 pizzas

Answer:

m<5 == m<1 since alternate interior angles are same value

m<3 == m<6 since alternate interior angles are same value

m<6 + m<5 + m<2 = m<1 + m<2 + m<3 = 180

Step-by-step explanation:

The use of alternate interior angles definition allows for you to make this completion.  You can use this since you have a line intersecting a point on two parallel lines.  From here, you know that the measures of the angles are the same as the measure of the line, thus you have proven the internal sum of angles to be 180 degrees.

Ans   k = 4

Step-by-step explanation:

Here g(x) =[tex]\frac{-1}{3}x + 1[/tex] and

        f(x) = [tex]\frac{-1}{3} x -3[/tex]

Now,  g(x) = f(x) + k

    or,      [tex]\frac{-1}{3}x + 1[/tex]  =  [tex]\frac{-1}{3} x -3 + k[/tex]

    or,      1 + 3 = k

    So,  k = 4   Answer.

Answer:  D.) The second difference is constant.

Step-by-step explanation:

The rate of change of a quadratic function is a linear function. The rate of change of that is constant, so second differences of a quadratic number pattern are constant.

Answer:

D.

Step-by-step explanation:

Answer:

A)Option D

B)P(X = 15) = 0.1325

Step-by-step explanation:

A) From the question, the information given follows binomial distribution because there are two mutually exclusive outcomes for each​ trial, there is a fixed number of trials. The outcome of one trial does not affect the outcome of ​another, and the probability of success is the same for each trial.

So option D is correct.

B) From the question, we are told that the poll reported that 66 percent of adults were satisfied with the job. Thus, probability is; p = 0.66

Let X be the number of adults satisfied with the job. Since 25 are selected,

Thus;

P(X = 15) = C(25, 15) * (0.66)^(15) * (1 - 0.66)^(25 - 15)

P(X = 15) = 3268760 × 0.00196407937 × 0.00002064378

P(X = 15) = 0.1325

Answer: 9/7 or -5/2

Step-by-step explanation:

We can only factorise quadratics if they're in the format ax^2 + bx + c

Re-arranging the equation gives 14x^2 + 17x - 45 = 0

Factorising this quadratic gives:

(7x - 9)(2x + 5) = 0

There are numerous ways to factorise quadratics, using a calculator or via alternate methods you may have learnt in class. (E.g. 2 numbers multiply to make (14 * -45) and add up to make (17).

This gives us our solutions.

x = 9/7 or x = -5/2

Answer:

See below.

Step-by-step explanation:

First, move all the terms to one side so we have only a zero on the right:

[tex]6x^2-17x+13=20x^2-32\\-14x^2-17x+45=0\\14x^2+17x-45=0[/tex]

(I divided everything by negative 1 in the third step. This is optional, but I like having the first term positive.)

Now, we just need to factor it. To factor, what you want to do is find two numbers a and b such that:

When a and b is multiplied together, they equal the first coefficient and constant multiplied together.

And when a and b is added together, they equal the second term.

In other words, we want to find two numbers that when multiplied equals 14(-45)=-630 and when added equals 17. Then, we can substitute this into the 17. You do this by guessing and checking. It's useful to have a calculator.

After a bit, you can find that 35 and -18 works. Thus:

[tex]14x^2+17x-45=0\\14x^2+35x-18x-45=0\\7x(2x+5)-9(2x+5)=0\\(7x-9)(2x+5)=0[/tex]

Now, the finish the problem, we just need to use the Zero Product Property and solve for x:

[tex]2x+5=0\\x=-5/2\\\\7x-9=0\\x=9/7[/tex]

Note: This only works for quadratics.

Answer:

2.8 cm

Step-by-step explanation:

The map scale is 1 cm : 5 km. That means that 1 cm is equal to 5 km.

To find the map distance (in cm), we have to set up a ratio.

[tex]\frac{1 cm}{5 km} = \frac{x}{14 km}[/tex]

X (the map distance in cm) is over the actual distance of 14 km.

Now cross multiply and divide.

[tex]5x = 14[/tex]

[tex]\frac{5x}{5} = \frac{14}{5}[/tex]

[tex]x = 2.8 cm[/tex]

If the actual distance to be represented is 14 km, the map distance (in cm) will be 2.8 cm.

Hope that helps.

(1) I assume "log" on its own refers to the base-10 logarithm.

[tex]\left(e^{-2x}\log(\ln x)^3\right)'=\left(e^{-2x}\right)'\log(\ln x)^3+e^{-2x}\left(\log(\ln x)^3\right)'[/tex]

[tex]=-2e^{-2x}\log(\ln x)^3+\dfrac{e^{-2x}}{\ln10(\ln x)^3}\left((\ln x)^3\right)'[/tex]

[tex]=-2e^{-2x}\log(\ln x)^3+\dfrac{3e^{-2x}(\ln x)^2}{\ln10(\ln x)^3}\left(\ln x\right)'[/tex]

[tex]=-2e^{-2x}\log(\ln x)^3+\dfrac{3e^{-2x}(\ln x)^2}{\ln10\,x(\ln x)^3}[/tex]

[tex]=-2e^{-2x}\log(\ln x)^3+\dfrac{3e^{-2x}}{\ln10\,x\ln x}[/tex]

Note that writing [tex]\log(\ln x)^3=3\log(\ln x)[/tex] is one way to avoid using the power rule.

(2)

[tex]\left(e^{-2x}(\log(\ln x))^3\right)'=(e^{-2x})'(\log(\ln x))^3+e^{-2x}\left(\log(\ln x))^3\right)'[/tex]

[tex]=-2e^{-2x}(\log(\ln x))^3+3e^{-2x}(\log(\ln x))^2(\log(\ln x))'[/tex]

[tex]=-2e^{-2x}(\log(\ln x))^3+3e^{-2x}(\log(\ln x))^2\dfrac{(\ln x)'}{\ln10\,\ln x}[/tex]

[tex]=-2e^{-2x}(\log(\ln x))^3+\dfrac{3e^{-2x}(\log(\ln x))^2}{\ln10\,x\ln x}[/tex]

(3)

[tex]\left(\sin(xe^x)^3\right)'=\left(\sin(x^3e^{3x})\right)'=\cos(x^3e^{3x}(x^3e^{3x})'[/tex]

[tex]=\cos(x^3e^{3x})((x^3)'e^{3x}+x^3(e^{3x})')[/tex]

[tex]=\cos(x^3e^{3x})(3x^2e^{3x}+3x^3e^{3x})[/tex]

[tex]=3x^2e^{3x}(1+x)\cos(x^3e^{3x})[/tex]

(4)

[tex]\left(\sin^3(xe^x)\right)'=3\sin^2(xe^x)\left(\sin(xe^x)\right)'[/tex]

[tex]=3\sin^2(xe^x)\cos(xe^x)(xe^x)'[/tex]

[tex]=3\sin^2(xe^x)\cos(xe^x)(x'e^x+x(e^x)')[/tex]

[tex]=3\sin^2(xe^x)\cos(xe^x)(e^x+xe^x)[/tex]

[tex]=3e^x(1+x)\sin^2(xe^x)\cos(xe^x)[/tex]

(5) Use implicit differentiation here.

[tex](\ln(xy))'=(e^{2y})'[/tex]

[tex]\dfrac{(xy)'}{xy}=2e^{2y}y'[/tex]

[tex]\dfrac{x'y+xy'}{xy}=2e^{2y}y'[/tex]

[tex]y+xy'=2xye^{2y}y'[/tex]

[tex]y=(2xye^{2y}-x)y'[/tex]

[tex]y'=\dfrac y{2xye^{2y}-x}[/tex]

Answer:

[tex]\large \boxed{\sf \ \ v_0=32 \ \ }[/tex]

Step-by-step explanation:

Hello,

The equation is

[tex]y=f(x)=-16x^2+v_0 \cdot x[/tex]

The ball hits the ground 2 seconds after the player kicks it, it means that f(2)=0.

We need to find [tex]v_0[/tex]  such that f(2)=0.

[tex]f(2)=-16\cdot 2^2+v_0 \cdot 2=-64+2v_0=0\\\\\text{*** add 64 to both sides ***}\\\\2v_0=64\\\\\text{*** divide by 2 both sides ***} \\\\v_0=\dfrac{64}{2}=32[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

Answer:

v0 = 32 ft/s

Step-by-step explanation:

Answer:

7/24

Step-by-step explanation:

7/8×3/8= 21/72

divide using 3

= 7/24

Answer:

x + 2y = 6

2y = -x + 6

y = -1/2x + 3

So, you will have a downward sloping, less steep line with an intercept at (0, 3).

You can use the Math is Fun Function Grapher and Calculator to graph the line.

Hope this helps!