Please help ( I will give brainliest)

256 square units

Step-by-step explanation:

The area of a square is the length of one of the sides of the square squared

First square's area:

(3x+7)^2

=9x^2+42x+49

Second square's area:

(5x+1)^2

=25x^2+10x+1

The squares are the identical, so the areas are equivalent

9x^2+42x+49=25x^2+10x+1

solve for x

9x^2+42x+49=25x^2+10x+1

-16x^2+32x+48=0

use the quadratic formula

x=-1, x=3

if you substitute x for -1 for both squares' sides, the blue side comes out positive but the green square's side comes out negative, which is impossible, so we can eliminate that answer.

substituting x=3 for the sides, we get 16 as the side for both.

16^2=256

256 square units is the answer.

36

step-by-step explanation: