How do you solve by factoring 5n^2- 17n= -6?

1 Answer
May 14, 2016

n = 2/5 or n = 3

Explanation:

First add 6 to both sides to get:

5n^2-17n+6 = 0

Then use an AC method:

Look for a pair of factors of AC = 5*6 = 30 with sum B=17.

The pair 15, 2 works.

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

5n^2-17n+6

= 5n^2-15n-2n+6

= (5n^2-15n)-(2n-6)

= 5n(n-3)-2(n-3)

= (5n-2)(n-3)

So our original equation becomes:

(5n-2)(n-3) = 0

with solutions:

n = 2/5 or n = 3