# Can y=3x^2-39x-90  be factored? If so what are the factors ?

Dec 16, 2015

#### Answer:

Factor y = 3x^2 - 39x - 90

Ans: y = (x +2)(x -15)

#### Explanation:

I use the new AC Method to factor trinomials (Socratic Search)
$y = 3 Y = 3 \left({x}^{2} - 13 x - 30\right)$. Factor Y = x^2 - 13x - 30).
Find 2 numbers knowing sum (b = -13) and product (c = -30)
Factor pairs of (-30) --> (-2, 15). This sum is 13 = -b. Then the opposite sum gives 2 numbers: 2 and - 15.

Factored form: $y = 3 \left(x + 2\right) \left(x - 15\right) =$