How do you divide (x^2-9)/(4x+12)div(x-3)/6?

2 Answers
May 24, 2015

((x - 3)(x + 3))/(2(x + 6)) . (6)/(x - 3) = (6(x + 3))/(2(x + 6))

May 24, 2015

First, notice that x^2-9 = x^2-3^2 = (x-3)(x+3)
This comes from a standard identity: (a^2 - b^2) = (a-b)(a+b)

So (x^2 - 9)/(x-3) = ((x-3)(x+3))/(x-3) = (x+3)

Hence

(x^2-9)/(4x+12)-:(x-3)/6

=(x+3)/(4x+12)-:1/6 =(6(x+3))/(4(x+3)) = 6/4 = 3/2