Asked by Matt

Factorise into quadratics

X^2-4x-21

X^2-4x+3

X^2+9x-36
Answered by Kuai

X^2-4x-21
(x+3)(x-7)

X^2-4x+3
(x -1)(x-3)

X^2+9x-36
(x +12)(x-3)