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

1 Answer
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 = 3Y = 3(x^2 - 13x - 30)#. 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(x + 2)(x - 15) =#