Your answer is B F(x) * (0.5)^x
(10+2x)(8+2x) = 120
4x^2 + 36x + 80 = 120
x^2 + 9x + 20 = 30
x^2 + 9x - 10 = 0
(x+10)(x-1) = 0
x = 1 inch dimension
The answer is for question 12, x = -9.3333333
I believe the correct answer would be 134.23568, forgive me if I am wrong