How do you factor 6y2+27y15?

1 Answer
Sep 19, 2016

6y2+27y15=3(2y1)(y+5)

Explanation:

First note that all of the coefficients are divisible by 3, so we can separate that out as a factor:

6y2+27y15=3(2y2+9y5)

We can factor the quadratic 2y2+9y5 using an AC method:

Find a pair of factors of AC=25=10 which differ by B=9

The pair 10,1 works.

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

2y2+9y5=(2y2+10y)(y+5)

2y2+9y5=2y(y+5)1(y+5)

2y2+9y5=(2y1)(y+5)

Putting it together:

6y2+27y15=3(2y1)(y+5)