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

1 Answer
Dec 26, 2015

Answer:

#= 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)#