Question

How do you factor `-15x^2+3x+12`?

Answer 1

y = - (15x + 12)(x - 1)

Explanation:

Use the new AC Method to factor trinomial (Google Search).
`f(x) = - y = - (15x^2 - 3x - 12)`
Factor y = (15x^2 - 3x - 12).
Since a + b + c = 0 use shortcut.
One real root is 1 and the factor is (x - 1)
One real root is c/a = - 12/15, and the factor is (x + 12/15)
Factored form:
`y = a(x - x1)(x - x2) = 15(x + 12/15)(x - 1) = (15x + 12)(x - 1)`
Finally:
`f(x) = - y = - (15x + 12)(x - 1)`