Solve for x: 2x^2 - 18 = 0

please give detailed steps!!

Answers

Answer 1

Answer:

[tex]x = 3[/tex]

or

[tex]x = - 3[/tex]

Step-by-step explanation:

Set up equation

[tex]2 {x}^{2} - 18 = 0[/tex]

Add 18 on both sides

[tex]2 {x}^{2} = 18[/tex]

Divide both sides by 2.

[tex] {x}^{2} = 9[/tex]

Take the square root of 9

Remeber square root solutions produce positive and negative Solutions.

[tex]x = 3[/tex]

[tex]x = - 3[/tex]


Related Questions

Evaluate the expression (-243)^2/5

Answers

Answer:

Step-by-step explanation:

The fifth root of -243 = - 3

If you now square  - 3, you get (-3)(-3) = 9

what is the perimeter of an equilateral triangular lamina of side length 12 cm​

Answers

Answer:

It is 36 cm

Step-by-step explanation:

In equilateral triangle, all sides are equal.

[tex]{ \sf{perimeter = side + side + side}}[/tex]

but side = 12 cm

[tex] { \sf{p = (12 + 12 + 12)}} \\ { \sf{p = 36 \: cm}}[/tex]

Answer: Perimeter = 36 cm

Concept:

Here, we need to know how to find the perimeter of an equilateral triangle.

An equilateral triangle is a triangle in which all three sides have the same length.

Perimeter (equilateral triangle) = 3s

s = side length

Solve:

Given information

Side length = 12 cm

Given expression

Perimeter = 3s

Substitute values into the expression

Perimeter = 3 (12)

Simplify by multiplication

Perimeter= [tex]\boxed{36cm}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

Rose's rectangular backyard has an area of 672 square meters. Find the length of the backyard if the backyard is 7 meters wide.​

Answers

Width=7mArea=672m^2

[tex]\\ \rm\longmapsto Length(Breadth)=Area[/tex]

[tex]\\ \rm\longmapsto Length(7)=672[/tex]

[tex]\\ \rm\longmapsto Length=\dfrac{672}{7}[/tex]

[tex]\\ \rm\longmapsto Length=96m[/tex]

Which statement is true about this equation?

Answers

Answer:

infinite solutions

Step-by-step explanation:

-9(x+3) +12 = -3(2x+5)-3x

Distribute

-9x-27 +12 = -6x-15-3x

Combine like terms

-9x -15 = -9x-15

Add 9x to each side

-9x-15+9x = -9x-15+9x

-15 = -15

This is a true statement so it is true for all x

20 points if these are correct pls.​

Answers

Answer:

16. 42

21. 18

Step-by-step explanation:

3 Which of the scientists responsible for cell theory would be the most likely to write a book titled Cells Come from Cells?


Hooke

Schleiden

Virchow

Schwann

Answers

Answer:

Virchow

Step-by-step explanation:

He was the one who discovered that all cells come from pre-existing cells, the third part of the cell theory.

11. Write in the expanded notation : (a) 85, 33, 48, 925 (b) 8, 25, 38, 201 (c) 2,00, 00, 63, 670 (d) 8,57,00, 07, 005 class 5

Answers

85 33 48 925800000000+50000000+3000000+300000+40000+8000+900+20+5

8 25 38 20180000000+2000000+500000+30000+8000+200+00+1

2 00 00 63 6702000000000+000000000+00000000+0000000+000000+60000+3000+600+70+0

8 57 00 07 0058000000000+500000000+70000000+0000000+000000+00000+7000+000+00+5

please mark this answer as brainlist

The speed of sound in dry air at 20° C (68° F) is 1.236 × 103 km/h. What is the speed of sound written as an ordinary number?

Answers

Step-by-step explanation:

The speed of sound has nothing to do with "sea level" and sound pressure and without the medium air there is no speed of sound. In SI units with dry air at 20°C (68°F), the speed of sound c is 343 meters per second (m/s). This also equates to 1235 km/h, 767 mph, 1125 feet per second (ft/s), or 666 knots.

Help!

Solve the equation: a/0.4 = –20

Answers

Answer:

i think this might be it? but most likely :) <3

Step-by-step explanation:

y = 10 when x = - 4 , find y when x = 12

Answers

Answer:

y = -30

Step-by-step explanation:

Set the ratio: [tex]\frac{x_1}{y_1} = \frac{x_2}{y_2}[/tex]

Let:

[tex](x_1 , y_1) = (-4 , 10)\\(x_2 , y_2) = (12 , y)\\[/tex]

Plug in the corresponding terms to the corresponding variables:

[tex]\frac{-4}{10} = \frac{12}{y}[/tex]

First, cross multiply.

[tex](-4 * y) = (10 * 12)\\-4y = 10 * 12\\-4y = 120[/tex]

Next, isolate the variable, y. Divide -4 from both sides of the equation:

[tex]\frac{-4y}{-4} = \frac{120}{-4}\\y = \frac{120}{-4}\\y = -30[/tex]

-30 is your answer for y.

37. Verify Green's theorem in the plane for f (3x2- 8y2) dx + (4y - 6xy) dy, where C is the boundary of the
C
region defined by: (a) y = fx , y = x2 ; (b) x = 0, y = 0, x +y = 1 .
Ans. (a) common value = 3/2 (b) common value = 5/3
38. Evaluate f (3x +4y)dx + (2x --3y)dy where C, a circle of radius two with center at the origin of the xy
C plane, is traversed in the positive sense. Ans. - 87T
39. Work the previous problem for the line integral f (x2+y2)dx + 3xy2 dy. Ans. 127T
C 40. Evaluate f (x2-2xy)dx +(x2y+3)dy around the boundary of the region defined by y2 = 8x and x = 2
(a) directly, (b) by using Green's theorem. Ans. 128/5
(TT.2) 41. Evaluate f (6xy - y2) dx + (3x2 --- 2xy) dy along the cycloid x = 6 - sin 6, y = 1 - cos 6.

Answers

I'll only look at (37) here, since

• (38) was addressed in 24438105

• (39) was addressed in 24434477

• (40) and (41) were both addressed in 24434541

In both parts, we're considering the line integral

[tex]\displaystyle \int_C (3x^2-8y^2)\,\mathrm dx + (4y-6xy)\,\mathrm dy[/tex]

and I assume C has a positive orientation in both cases

(a) It looks like the region has the curves y = x and y = x ² as its boundary***, so that the interior of C is the set D given by

[tex]D = \left\{(x,y) \mid 0\le x\le1 \text{ and }x^2\le y\le x\right\}[/tex]

• Compute the line integral directly by splitting up C into two component curves,

C₁ : x = t and y = t ² with 0 ≤ t ≤ 1

C₂ : x = 1 - t and y = 1 - t with 0 ≤ t ≤ 1

Then

[tex]\displaystyle \int_C = \int_{C_1} + \int_{C_2} \\\\ = \int_0^1 \left((3t^2-8t^4)+(4t^2-6t^3)(2t))\right)\,\mathrm dt \\+ \int_0^1 \left((-5(1-t)^2)(-1)+(4(1-t)-6(1-t)^2)(-1)\right)\,\mathrm dt \\\\ = \int_0^1 (7-18t+14t^2+8t^3-20t^4)\,\mathrm dt = \boxed{\frac23}[/tex]

*** Obviously this interpretation is incorrect if the solution is supposed to be 3/2, so make the appropriate adjustment when you work this out for yourself.

• Compute the same integral using Green's theorem:

[tex]\displaystyle \int_C (3x^2-8y^2)\,\mathrm dx + (4y-6xy)\,\mathrm dy = \iint_D \frac{\partial(4y-6xy)}{\partial x} - \frac{\partial(3x^2-8y^2)}{\partial y}\,\mathrm dx\,\mathrm dy \\\\ = \int_0^1\int_{x^2}^x 10y\,\mathrm dy\,\mathrm dx = \boxed{\frac23}[/tex]

(b) C is the boundary of the region

[tex]D = \left\{(x,y) \mid 0\le x\le 1\text{ and }0\le y\le1-x\right\}[/tex]

• Compute the line integral directly, splitting up C into 3 components,

C₁ : x = t and y = 0 with 0 ≤ t ≤ 1

C₂ : x = 1 - t and y = t with 0 ≤ t ≤ 1

C₃ : x = 0 and y = 1 - t with 0 ≤ t ≤ 1

Then

[tex]\displaystyle \int_C = \int_{C_1} + \int_{C_2} + \int_{C_3} \\\\ = \int_0^1 3t^2\,\mathrm dt + \int_0^1 (11t^2+4t-3)\,\mathrm dt + \int_0^1(4t-4)\,\mathrm dt \\\\ = \int_0^1 (14t^2+8t-7)\,\mathrm dt = \boxed{\frac53}[/tex]

• Using Green's theorem:

[tex]\displaystyle \int_C (3x^2-8y^2)\,\mathrm dx + (4y-6xy)\,\mathrm dx = \int_0^1\int_0^{1-x}10y\,\mathrm dy\,\mathrm dx = \boxed{\frac53}[/tex]

What is the largest amount which can be borrowed over three years at 4.5% APR if the largest
affordable monthly payment is $279? (Round to the nearest ten dollars.)

Answers

Answer:

$12.5 dollars

Step-by-step explanation:

cc

find the slope of the line

Answers

Answer:

m = (6-5)/(4-1)

m = 1/3

.............

A box of 8 cellphones contains two yellow cellphones and six green cellphones. Complete parts (a) through (d) below.
a. If two cellphones are randomly selected from the box without replacement, what is the probability that both cellphones selected will be green?
b. If two cellphones are randomly selected from the box without replacement, what is the probability there will be one green cellphone and one yellow cellphone selected?
c. If three cellphones are selected with replacement (the first cellphone is returned to the box after it is selected), what is the probability that all three will be yellow?
d. If you were sampling with replacement (the first cellphone is returned to the box after it is selected), what would be the answers to (a) and (b)?

Answers

Probabilities are used to determine the chance of an event. The following are the summary of the solution.

The probability that the two selected cellphones are green (without replacement) is 15/28The probability that one green and one yellow is selected (without replacement) is 3/7The probability that all three cellphones are yellow (with replacement) is 1/64The probability that the two cellphones are green (with replacement) is 9/16The probability that one green and one yellow is selected (with replacement) is 3/8

Given that:

[tex]n = 8[/tex]

[tex]G = 6[/tex] --- Green

[tex]Y = 2[/tex] --- Yellow

(a) Probability that the two cellphones are green (without replacement).

Since the cellphone is not replaced, the probability is calculated as follows:

[tex]Pr = \frac Gn \times \frac{G - 1}{n-1}[/tex]

So, we have:

[tex]Pr = \frac 68 \times \frac{6 - 1}{8-1}[/tex]

[tex]Pr = \frac 68 \times \frac 57[/tex]

[tex]Pr = \frac{30}{56}[/tex]

[tex]Pr = \frac{15}{28}[/tex]

Hence, the probability that the two cellphones are green (without replacement) is 15/28

(b) Probability that one green and one yellow is selected (without replacement).

Since the cellphone is not replaced, the probability is calculated as follows:

[tex]Pr = \frac Gn \times \frac{Y}{n-1} + \frac Yn \times \frac{G}{n-1}[/tex]  ---- The subtraction means the cellphones are not replaced

This gives

[tex]Pr = \frac 68 \times \frac{2}{8-1} + \frac 28 \times \frac{6}{8-1}[/tex]

[tex]Pr = \frac 34 \times \frac{2}{7} + \frac 14 \times \frac{6}{7}[/tex]

[tex]Pr = \frac 32 \times \frac17 + \frac 12 \times \frac 37[/tex]

[tex]Pr = \frac{3}{14} + \frac{3}{14}[/tex]

Take LCM

[tex]Pr = \frac{3+3}{14}[/tex]

[tex]Pr = \frac{6}{14}[/tex]

[tex]Pr = \frac{3}{7}[/tex]

Hence, the probability that one green and one yellow is selected (without replacement) is 3/7

(c) Probability that the all three cellphones are yellow (with replacement).

Since the cellphone is replaced, the probability is calculated as follows:

[tex]Pr = \frac Yn \times \frac Yn \times \frac Yn[/tex]

So, we have:

[tex]Pr = \frac 28 \times \frac 28 \times \frac 28[/tex]

[tex]Pr = \frac 14 \times \frac 14 \times \frac 14[/tex]

[tex]Pr = \frac 1{64}[/tex]

Hence, the probability that all three cellphones are yellow (with replacement) is 1/64

(d1) Probability that the two cellphones are green (with replacement).

Since the cellphone is replaced, the probability is calculated as follows:

[tex]Pr = \frac Gn \times \frac{G}{n}[/tex]

So, we have:

[tex]Pr = \frac 68 \times \frac{6}{8}[/tex]

[tex]Pr = \frac 34 \times \frac{3}{4}[/tex]

[tex]Pr = \frac{9}{16}[/tex]

Hence, the probability that the two cellphones are green (with replacement) is 9/16

(d2) Probability that one green and one yellow is selected (with replacement).

Since the cellphone is replaced, the probability is calculated as follows:

So, we have:

[tex]Pr = \frac Gn \times \frac{Y}{n} + \frac Yn \times \frac{G}{n}[/tex]

This gives

[tex]Pr = \frac 68 \times \frac{2}{8} + \frac 28 \times \frac{6}{8}[/tex]

[tex]Pr = \frac 34 \times \frac{1}{4} + \frac 14 \times \frac{3}{4}[/tex]

[tex]Pr = \frac 3{16} + \frac{3}{16}[/tex]

Take LCM

[tex]Pr = \frac {3+3}{16}[/tex]

[tex]Pr = \frac {6}{16}[/tex]

[tex]Pr = \frac {3}{8}[/tex]

Hence, the probability that one green and one yellow is selected (with replacement) is 3/8

Read more about probabilities at:

https://brainly.com/question/795909

Help with number 7 picture above

Answers

9514 1404 393

Answer:

  next: ←, ↑, →, ↓, ←

Step-by-step explanation:

It appears you want to identify a rule describing the sequence, then provide several additional elements in the sequence.

It looks to me like each successive element has been rotated 90° CW from the previous one.

Continuing that pattern, the arrows will point left, up, right, down, left.

ANSWeR RIGHT ANDIL ALSO GIVE 5 STAR AND BRAINLIEST

Answers

Answer:

3. Sanford Township, Minnesota

4. Inner Mongolia, China

5. Arunachal Pradesh, India

6.Almaty Region, Kazakhstan

7.Madhya Pradesh, India

Step-by-step explanation:

Find the solution set
2(x + 4 = 8

Answers

Answer:

x=0

Step-by-step explanation:

0+4=4

4x2=8

it's pretty simple once you get the hang of it

2 ❌= 8 ➕4


Well the answer is 6

The sum of three times a number, x, and 12

Answers

Answer:

The sum of three times a number and twelve is fewer than twenty translates into an inequality

3x+12 < 20

Step-by-step explanation:

it's not the perfect answer of your question but it's kind of similar to it

Find the value of x.​

Answers

Answer:

x=60

Step-by-step explanation:

x=180-120

Plane P is a cross-section of the solid below. What shape is the cross section?

A. not enough information

B. hexagon

C. pentagon

D. rectangle

Answers

Answer:

B. hexagon

Step-by-step explanation:

HELP NOW PLEASE NOW ILL GIVE YOU BRAINLY IF YOU GET IT RIGHT NOW PLEASE!!!

Answers

Answer:

you can check the picture, i tried to make it as simple as possible. so I answered by the format.

Find the sum.
1/xy^2 + x^2/y

Answers

Answer:

Step-by-step explanation:

If UW = 9x - 9, what is UW in units?
5
6
30
36

Answers

Answer: UW is 36 units long

Explanation:
UW is composed of UV and VW, which we have values for. So, let’s make an equation.

(2x - 4) + (4x + 10) = 9x - 9

Solve the left side

6x + 6 = 9x - 9

Subtract 6 from both sides

6x = 9x - 15

Subtract 9x from both sides

-3x = -15

Divide both sides by -3

x = 5

Plug 5 into the equation for UW.

9(5) - 9

45 - 9

36
The answer is 36 Uw in units .

(2.5*10^3)*3.4*10^2 (in scientific notation)​

Answers

Answer:

8.5 × 10^5

Step-by-step explanation:

Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the 10. If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.

[tex]\\ \rm\Rrightarrow (2.5\times 10^3)^3\times 4\times 10^2[/tex]

[tex]\\ \rm\Rrightarrow 2.5\times 3.4 10^3 \times 10^2[/tex]

[tex]\\ \rm\Rrightarrow 8.5\times 10^{3+2}[/tex]

[tex]\\ \rm\Rrightarrow 8.5\times 10^5[/tex]

Convert 2 yards to centimeters. Round to the nearest whole
centimeter.

Answers

Answer:

183 centimeters

Step-by-step explanation:

2 multiply the length value by 91.44

the selling price of an article is 20% less than its marked price and the marked price is 30% above the cost price. find the profit percent.​

Answers

Step-by-step explanation:

here,

let MP be x then,

SP=x-20%of X

=x - 20x/100

=x- 0.2x

=0.8x

CP= x- 30% of x

= x- 30x/100

=x- 0.3x

=0.7x

now,profit (P) = SP -CP

= 0.8x-0.7x

=0.1x

so,

P%=( P\CP ) ×100%

= (0.1x/0.7x) ×100%

= 14.28 %

Your college professor tells you he will give a 30%-30%-40% split on grades between homework, quizzes, and test. However whichever category you have the highest average in will be the 40% category.

What will your final grade be if your homework average is 53, you quiz average is 66, and your test average is 96?

Answers

Answer: 74.1

Explanation:

53 x 30/100 = 15.9

66 x 30/100 = 19.8

96 x 40/100 = 38.4

38.4 + 19.8 + 15.9 = 74.1

Therefore, the final grade is 74.1

please help me it's for today

Answers

Check the pictures attached for the answers.

Round each number to the nearest hundredth.
a. 8.7495980
b. 0.72091
C. 9.3113
d. 23.0368
e 6.9788

Answers

Answer:

a. 8.75

b. 0.72

c. 9.31

d. 23.04

e. 6.98

Step-by-step explanation:

a.

in this number 8.7495980

the digit in the hundredth place is 4

the digit in the thousandth  place is 9

Since 9 ≥ 5 ,then 8.7495980 rounded to nearest hundredth is :

8,75

b.

in this number 0.72091

the digit in the hundredth place is 2

the digit in the thousandth  place is 0

Since 0 < 5 ,then  0.72091 rounded to nearest hundredth is :

0.72

c.

in this number 9.3113

the digit in the hundredth place is 1

the digit in the thousandth  place is 1

Since 1 < 5 ,then  9.3113 rounded to nearest hundredth is :

9.31

d.

in this number 23.0368

the digit in the hundredth place is 3

the digit in the thousandth  place is 6

Since 6 ≥ 5 ,then 23.0368 rounded to nearest hundredth is :

23.04

e.

in this number 6.9788

the digit in the hundredth place is 7

the digit in the thousandth  place is 8

Since 8 ≥ 5 ,then 6.9788 rounded to nearest hundredth is :

6.98

refer to image given and please answer!!!!!

Answers

Step-by-step explanation:

According to the quotient rule of differentiation, if [tex]y(x) = u(x)/v(x),[/tex] then its derivative is given by

[tex]\dfrac{dy}{dx} = \dfrac{v\dfrac{du}{dx} - u\dfrac{dv}{dx}}{v^2}\:\:\:\:\:\:\:\:\:(1)[/tex]

We can see that

[tex]u(x) = \ln (4x^2 + 1)[/tex]

[tex]\dfrac{du}{dx} = \dfrac{8x}{4x^2 + 1}[/tex]

[tex]v(x) = 2x - 3[/tex]

[tex]\dfrac{dv}{dx} = 2[/tex]

Plugging the above expressions into Eqn(1), we find that the derivative is

[tex]\dfrac{dy}{dx} = \dfrac{\dfrac{8x(2x - 3)}{(4x^2 + 1)} - 2\ln (4x^2 + 1)}{(2x - 3)^2}[/tex]

[tex]\:\:\:\:\:\:\:= \dfrac{8x}{(4x^2 + 1)(2x - 3)} - \dfrac{2\ln (4x^2 + 1)}{(2x - 3)^2}[/tex]

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