Question

The first one is done and the options for number four are:

w(2w+12)=160
2w^2+12w-260=0
2w^2+12w=260
w^2+6w-130=0

Answer 1

Explanation:

Part A

w² + 6w + c = 130 + c

w² + 2(3w) + c = 130 + c

To make left side of the equation a perfect square we will replace c by (3)².

w² + 2(3w) + 3² = 130 + c

[By formula → a² + 2ab + b² = (a + b)²]

w² + 2(3w) + 9 = 130 + 9

Therefore, c = 9 will be the answer.

Part B

From part A,

(w + 3)² = 139

Option (2) and Option (6) are the correct options.

Part C

w + 3 = √139

w = 11.79 - 3

w = 8.79

w ≈ 8.8 inches