Question

How do you factor completely `36+3x-3x^2`?

Answer 1

Factor `y = -3x^2 + 3x + 36 = -3(x^2 - x - 12)`

Explanation:

Factor `f(x) = x^2 - x - 12.`
Compose factor pairs of (-12) --> (-2, 6)(-3, 4). This sum is 1 = -b. Then the factor are (x + 3) and (x - 4)

y = -3(x + 3)(x - 4)