Question

Factorise

(X²-5x)²-8(x²-5x)-84

Answer 1

Let (x²-5x)be a

a²-8a-84

a²-14a+6a-84

a(a-14)+6(a-14)

(a-14)(a+6)

put x²-5x in a

(x²-5x-14)(x²-5x+6)

(x²+2x-7x-14)(x²-2x-3x+6)

{x(x+2)-7(x+2)}{x(x-2)-3(x-2)}

(x+2)(x-7)(x-2)(x-3)

Answer