How do you factor the expression 12y^5 – 34xy^4 + 14x^2y^3?

1 Answer
Apr 24, 2016

12y^5-34xy^4+14x^2y^3=2y^3(3y-7x)(2y-x)

Explanation:

First note that all of the terms are divisible by 2y^3, so separate that out as a factor first:

12y^5-34xy^4+14x^2y^3=2y^3(6y^2-17xy+7x^2)

The remaining factor is homogeneous of degree 2, so we can attempt to factor it using an AC method.

Look for a pair of factors of AC = 6*7 = 42 with sum B=17.

The pair 3, 14 works, in that 3*14 = 42 and 3+14=17.

Use this pair to split the middle term and factor by grouping:

6y^2-17xy+7x^2

=6y^2-3xy-14xy+7x^2

=(6y^2-3xy)-(14xy-7x^2)

=3y(2y-x)-7x(2y-x)

=(3y-7x)(2y-x)

Putting it all together:

12y^5-34xy^4+14x^2y^3=2y^3(3y-7x)(2y-x)