Question

How do you simplify and find the excluded value of `(d+7)/(d^2-49)`?

Answer 1

`1/(d-7)` and `d!=+-7`

Explanation:

The first approach with algebraic fractions is to see if you can find factors.

`(d+7)/(d^2-49) " "larr` difference of squares

`=((d+7))/((d+7)(d-7))" "larr d!=+-7`

`cancel((d+7))/(cancel((d+7))(d-7)`

`=1/(d-7)`