Question

How do you multiply `1/(x+9)*(7x^3+49x^2)/(x+7)` and state the excluded values?

Answer 1

`(7x^2)/(x+9)`

Explanation:

`1/(x+9)*(7x^3+49x^2)/(x+7)`

We can state the excluded values immediately because the denominators may not be 0.

`x !=-9 and x!=-7`

Factorise first to see there are common factors which can cancel

. `1/(x+9)xx(7x^2cancel((x+7)))/cancel((x+7))`

=`(7x^2)/(x+9)`