Question

Each side of a square is increased 7 inches. when this happens, the area is multiplied by 4. how many inches in the side of the original square?

Answer 1

Hello,

Assume x the side of the square.

(x+7)²=4x²
==> ((x+7)-2x)((x+7)+2x)=0
==> (-x+7)(3x+7)=0
==> x=7 or x=-7/3 (to exclude since side must be positive)

Proof:
(7+7)²=196
4*49=196