How do you factor the trinomial 7u^2+26u-8?

1 Answer
Oct 21, 2016

(7u-2)(u+4)

Explanation:

color(red)(7)u^2+color(blue)26ucolor(red)(-8)

For expansion, first
multiply color(red)7 with color(red)(-8), which is =-56, then

Find 2 numbers whose product is -56 and sum is color(blue)26, that is color(green)28 and color(green)(-2).

Factorization by expansion :
7u^2+color(green)(28u-2u)-8

Now, take common on first 2 terms and last 2 terms seperately,
7u(u+4)-2(u+4)

Further, taking common on (u+4):
(7u-2)(u+4)