Question

Factorize each of the following expression:
9(a − b)² − 100(x − y)²

Answer 1

$$\begin{gathered} 9(a-b{)}^2-100(x-y{)}^2 \\ =\left[3\right(a-b){]}^2-[10(x-y){]}^2 \\ =\left[3\right(a-b)-10(x-y\left)\right]\left[3\right(a-b)+10(x-y\left)\right] \\ =(3a-3b-10x+10y)(3a-3b+10x-10y) \end{gathered}$$