How do you factor the trinomial #3y^4 -12y^3 -15y^2#?

1 Answer
Feb 1, 2016

#3y^4-12y^3-15y^2=3y^2(y+1)(y-5)#

Explanation:

#3y^4-12y^3-15y^2#

Factor out the GCF #3y^2#.

#3y^2(y^2-4y-5)#

Factor #y^2-4y-5#.

Find two numbers that when multiplied equal #-5# and when added equal #-4#. The numbers #-5# and #1# fit the pattern.

Rewrite #y^2-4y-5# as #(y+1)(y-5)#.

Add back the GCF #3y^2# and rewrite the expression.

#3y^2(y+1)(y-5)#