Question

How do you simplify `(10y-30)/(y^2-1)`?

Answer 1

By factorization:

`color(red)[10(y-3)]/(y^2-1)`

`[10(y-3)]/color(red)[(y)^2-(1)^2]`

Recall: `rArr (a)^2-(b)^2=(a+b)(a-b)`

So;

`color(green){[10(y-3)]/[(y+1)(y-1)]`