WAEC 2019 · Paper 1 · Q31

Factorize completely $(2x + 2y)(x - y) + (2x - 2y)(x + y)$ .

Worked solution (try it first)

Take out 2 from the first bracket of each term: $2(x + y)(x - y) + 2(x - y)(x + y)$ .
The two terms are equal, so together they make $4(x + y)(x - y)$ .
So the expression is $4(x - y)(x + y)$ , option A.