Question

How do you solve `8x - x^2 = 15`?

Answer 1

Re-write the equation in standard form; then factor to get
`color(white)("XXX")x=3` or `x=5`

Explanation:

`8x-x^2=15`

`hArr x^2-8x+15=0`

`hArr (x-3)(x-5)=0`

`(x-3)=0 rarr x=3`
or
`(x-5)=0 rarr x=5`