Question

How do you factor `v^ { 2} + 17v - 18`?

Answer 1

Playing with the multiples of `18` (1x18, 2x9, 3x6) gives a factor of:

`(v + 18)(v - 1)`

Answer 2

`(v-1)(v+18)`

Explanation:

Find two numbers that multiple to `-18` and sum to `+17`

`(1)(-18) = -18`, but `1+ (-18) = -17` not `+17`

`(-1)(18)= -18`, and `-1 + 18 = 17`

So: `v^2+17v-18 = (v-1)(v+18)`