Question

Solve:
$\frac{m^2-3m-108}{m+9}=0,$ then $m=?$

Answer 1

We solve the given expression $\frac{m^2-3m-108}{m+9}=0$ as shown below:

$\frac{m^2-3m-108}{m+9}=0\Rightarrow m^2-3m-108=0\times (m+9)\Rightarrow m^2-3m-108=0\Rightarrow m^2-12m-9m+108=0\Rightarrow m(m-12)-9(m-12)=0\Rightarrow (m-9)(m-12)=0\Rightarrow (m-9)=0,(m-12)=0\Rightarrow m=9,m=12$

Hence, $m=9,12$.