Can #y=2x^2+9x-5# be factored? If so what are the factors ?

1 Answer
Mar 30, 2016

(2x - 1)(x + 5)

Explanation:

#y = 2x^2 + 9x - 5 = #2(x + p)(x + q)
Converted trinomial #y' = x^2 + 9x - 10 =# (x + p')(x + q').
p' and q' have opposite signs. Factor pairs of (-10) --> (-1, 10). This sum is 9 = b. Then p' = -1 and q = 10.
Back to y, #p = -1/2# and q = 10/2 = 5
#y = 2(x - 1/2)(x + 5) = (2x - 1)(x + 5)#