Question

Jillian is trying to save water, so she reduces the size of her square grass lawn by 8 feet on each side. The area of the smaller lawn is 144 square feet. In the equation
(x – 8)2 = 144, x represents the side measure of the original lawn.

What were the dimensions of the original lawn?

4 feet by 4 feet
8 + 6 StartRoot 2 EndRoot feet by 8 + 6 StartRoot 2 EndRoot
8 Minus 6 StartRoot 2 EndRoot feet by 8 + 6 StartRoot 2 EndRoot
20 feet by 20 feet

Answer 1

Solve (x − 8)^2 = 144. Taking square roots gives x − 8 = ±12. The positive solution is x − 8 = 12 → x = 20 (the negative root x = −4 is impossible for a side length).

So the original lawn was 20 feet by 20 feet.