# What are the excluded values for the rational expression (5d+15)/(d^2-d-12)?

Aug 6, 2017

$d \ne - 3 \mathmr{and} d \ne 4$

#### Explanation:

the excluded values are those which will make the denominator equal to $0$

Factorise to find the factors

$\frac{5 \left(d + 3\right)}{\left(d - 4\right) \left(d + 3\right)}$

$d \ne - 3 \mathmr{and} d \ne 4$