Question

Completely factor this quadratic expression: 4x2 + 12x − 72.

Answer 1

(4x² + 24x)- (12x + 72)

4x( x+ 6)- 12(x + 6)

ans = (4x - 12)(x + 6)

Answer 2

4(x-3)(x+6)

Explanation:

Factor out the 4

4(x2 + 3x - 18)

what 2 numbers add to 3 and multiply to - 18?

-3 and 6

therefore 4x2 + 12x − 72 = 4(x-3)(x+6)