How do you factor completely 7y^3 - 21y^2 - 2y + 6?

1 Answer
Dec 26, 2015

= color(green)((7y^2-2)(y-3)

Explanation:

color(blue)(7y^3-21y^2)color(green)(-2y+6

Factorising by grouping :

(7y^2) is common to both the terms in the first group, and -2 is common to both the terms in the second group:

We can factor this expression by making groups of two terms:
7y^2(y-3) -2(y-3)

y-3 is common to both the terms now:

= color(green)((7y^2-2)(y-3)