How do you factor 8x^2+65x+8?

1 Answer
Aug 9, 2015

Factor y = 8x^2 + 65x + 8

Ans: (8x + 1)(x + 8)

Explanation:

Use the new AC Method. y = 8(x - p)(x - q).
Converted trinomial y' = x^2 + 65x + 64 = (x - p')(x - q').
p' and q' have same sign (a and c same sign)
Factor pairs of 64 -> (1, 64). This sum is 65 = b.
Then p' = 1 and q' = 64.
Therefor, p = (p')/a = 1/8 and q = 64/8 = 8

y = 8(x + 1/8)(x + 8) = (8x + 1)(x + 8)