Question

Which of the following represents the area of a rectangle whose length is x − 7 and whose width is x + 12?

Answer 1

(x-7)(x+12)
X^2 +12x-7x-84

x^2+5x-84. <- answer

Answer 2

Answer:

$A=(x^{2}+5x-84)\ units^{2}$

Step-by-step explanation:

we know that

The area of a rectangle is equal to

$A=WL$

where

W is the width of the rectangle

L is the length of the rectangle

In this problem we have

$L=(x-7)\ units$

$W=(x+12)\ units$

substitute

$A=(x-7)(x+12)\\A=x^{2}+12x-7x-84\\A=(x^{2}+5x-84)\ units^{2}$