Question

How do I factor -9x+20+x^2?

Answer 1

`(x-4)(x-5)`

Explanation:

Factors of 20
`1xx20`
`2xx10`
`4xx5`

`x^2-9x+20`
`=(x-4)(x-5)`

To check,
`-4-5=-9`
`-4xx(-5)=20`