How do you factor #8u^2 + 6u - 9#?

1 Answer
Jun 16, 2015

Answer:

#8u^2+6u-9 = (2u+3)(4u-3)#

Explanation:

We need to look at factors of
#color(white)("XXXX")## 8#
#color(white)("XXXX")## (a,b) epsilon {(1,8), (2,4)}#
and
#color(white)("XXXX")## (-9)#
#color(white)("XXXX")##(c,d) epsilon {(1,-9), (-1,9), (3,-3), (-3,3)}#

such that
#color(white)("XXXX")##ac - bd = +6#

then plug them into
#color(white)("XXXX")##(au+c)(bu+d)#