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2 years ago

Which sentence explains the correct first step in the solution of this equation?

Mathematics

1 answer:

siniylev [52]2 years ago

3 0

Answer:

<h3>B. Apply the distributive property to get 4x-12=9</h3>

$\boxed{\sf{x=\dfrac{21}{4}=5.25 }}$

Step-by-step explanation:

Isolate the term of x from one side of the equation.

Use the distributive property.

<u>Distributive property:</u>

$\Longrightarrow: \sf{A(B+C)=AB+AC}$

<u>Expand the form multiply.</u>

4*x=4x

4*3=12

<u>Rewrite the problem down.</u>

4x-12=9

<u>Add by 12 from both sides.</u>

4x-12+12=9+12

<u>Solve.</u>

<u />

<u>Add the numbers from left to right.</u>

9+12=21

4x=21

Divide by 4 from both sides.

4x/4=21/4

<u>Solve.</u>

<u>Divide the numbers from left to right.</u>

x=21/4

21/4=5.25

<u>Therefore, the final answer is x=21/4=5.25.</u>

I hope this helps you! Let me know if my answer is wrong or not.

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(x^2-4x)^2+7x^2-28x+12=0

Valentin [98]

Answer:

$x^4-9x^2-28x=-12$

Step-by-step explanation:

$(x^2-4x)^2+7x^2-28x+12=0$

$(x^4-16x^2)+7x^2-28x=-12$

$x^4-9x^2-28x=-12$

7 0

3 years ago

The length of the rectangle is 5 inches more than the width. The perimeter of the rectangle is 42 inches. Write an equation to m

Sunny_sXe [5.5K]

Answer:

<h2>Length = 13 in. </h2>

Step-by-step explanation:

perimeter of a rectangle (P) = 2L + 2W

where;

P = 42 in.

Length (L) = 5 + W

Find:

length (L) of the rectangle

solution:

P = 2L + 2W

42 = 2(5 + W) + 2W

42 = 10 + 2W + 2W

42 - 10 = 4W

32 = 4W

W = 32/4

W = 8

Length (L) = 5 + W

= 5 + 8

= 13 in

proof:

42 = 2(13) + 2(8)

42 = 42 in

4 0

3 years ago

The perimeter of a triangle is 27. Each side of the triangle has length 2x-3. What is the value of x?

Bezzdna [24]

Answer:

x=6

Step-by-step explanation:

To find the perimeter of the triangle you need to add up all the sides, so if all the sides are 2x-3 the equation will look like this;

2x-3+2x-3+2x-3=27

which when combining like terms will leave it to be;

6x-9=27

Than move all the factors besides x over to the right side;

6x-9+9=27+9

6x = 36

6x/6 = 36/6

x = 6

so your answer will be x=6

8 0

3 years ago

Please help as fast as you cannn

hodyreva [135]

Answer:

-43 < -35

(Negative 43 is less than negative 35).

8 0

3 years ago

a famer has 120 feet of fencing with whcih to enclose two adjacent rectangular pens as shown. what dimeensions should be used th

Nat2105 [25]

The dimensions of the rectangular pen should be 15 by 20 feet and the maximum area is 1200 square feet.

Let the area be y .

Area = (base) × (height)

Base = 2x

Height = h

Let the area of the rectangular pens be y .

∴ y = 2xh

Perimeter of all the fencing = 4x+3h

∴ 4x+3h = 120

now we solve for h

3h = 120-4x

h = 40 - 4/3 x

Now we will substitute this value in the above first equation:

y = 2xh

or, y = 2x (40 - 4/3 x)

or, y = 80x - 8/3 x²

Now for the maximum area we have to find the first order differentiation of y

now,

dy /dx = 80 - 16/3 x

At dy/dx = 0 we get the value of x for which y is maximum.

80 - 16/3 x = 0

or, - 16/3 x = -80

or, x = 15 feet

Hence height = 40 - 4/3 x = 40 - 20 = 20feet

Maximum area = 2xh = 2×15×40 = 1200 square feet

The dimensions of the rectangular pen should be 15 by 20 feet and the maximum area is 1200 square feet.

Disclaimer : The missing figure for the question is attached below.

To learn more about area visit:

brainly.com/question/27531272

#SPJ4

6 0

1 year ago