WAEC 2023 · Paper 1 · Q8

Factorize completely: $x^2 - (y + z)^2$ .

Worked solution (try it first)

Use the difference of two squares with $A = x$ and $B = y + z$ : $x^2 - (y + z)^2 = [x + (y + z)][x - (y + z)]$ .
Remove the inner brackets: $x - (y + z) = x - y - z$ .
So the factors are $(x + y + z)(x - y - z)$ , option B.