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Which statement is true of a rectangle that has an area of 4x2 + 39x – 10 square units and a width of (x + 10) units?

A) The rectangle is a square.

B) The rectangle has a length of (2x – 5) units.

C) The perimeter of the rectangle is (10x + 18) units.

D) The area of the rectangle can be represented by (4x2 + 20x – 2x – 10) square units.

User Skewled
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2 Answers

2 votes

Answer:

C) The perimeter of the rectangle is (10x + 18) units.

Explanation:

First we will find the length by dividing the polynomials.

We first put the dividend, 4x²+39x-10, under the box. The divisor, x+10, goes on the outside of the box (to the left).

We divide 4x² by x; this is 4x. We put 4x above 39x in the quotient.

Next we multiply back through by 4x:

4x(x+10) = 4x²+40x. This goes under 4x²+39x in the dividend. We subtract, giving us -1x. We then bring down the -10, giving us the expression -1x-10.

We divide -1x by x. This is -1. This goes beside the 4x in the quotient. We multiply back through by -1:

-1(x+10) = -1x-10. This goes under the -1x-10 in the work. Subtracting cancels both of these, leaving us with the quotient 4x-1.

This is not the same as the width, so the rectangle is not a square. The length was not 2x-5.

The perimeter is found by adding

(4x-1)+(4x-1)+(x+10)+(x+10)

Combining like terms, we have

4x+4x+x+x-1-1+10+10

10x+18 is the perimeter.

User Egga Hartung
by
8.0k points
5 votes

Answer:

its C

Explanation:

its c

User Luca Faggianelli
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8.2k points