The area of one square is x^2 + 6x + 9 and the area of another square is 4x^2 − 28x + 49. If the sum of the perimeters of both squares is 56, what is the value of x?
Choose the correct choice from the following answers.
A) 3
B) 4
C) 5
D) 6
E) 7
The areas are (x+3)^2 and (2x-7)^2.   The lengths of the sides are x+3 and 2x-7.   If we add the two perimeters:   4(x+3) + 4(2x-7) = 56   12x = 72   x = 6   The answer is 6.
<result>D</result>
The area of one square is x^2 + 6x + 9 and the area of another square is 4x^2 − 28x + 49. If the sum of the perimeters of both squares is 56, what is the value of x?