Question

Forming a Quadratic Equation.
http://gyazo.com/e6be095977e9fd0f2a91681855bfdd39

Answer 1

the outer rectangle (= painting + frame) needs to have an Area A of
length times height and should equal 75
A = L times H = 75

L = 9 + 2x

and
H = 8 + 2x

so
A = L times H = (9+ 2x)(8+2x) = 75
A = 4x^2 + 34x + 72 =75

So we find
4x^2 + 34x -3 = 0

That is the last option

Answer 2

@abtster Thanks.