Question

How to factor this so that it's in parenthesis? (Please use a detailed explanation thanks)

8n^2 -14n -15

Answer 1

(4n+3)(2n-5)

Explanation:

1) Split the second term
`8n^2-14n-15` into two terms.

1- Multiply the coefficient of the first term by the constant term.

`8*-15=-120`

2- Ask: Which two numbers add up to -14 and multiply to -120?

6 and -20

3- Split -14n as the sum of 6n and -20n.

`8n^2+6n-20n-15`

2) Factor out common terms in the first two terms, then in the last two terms.

`2n(4n+3)-5(4n+3)`

3) Factor out the common term
`4n+3`.

`(4n+3)(2n-5)`