Find the Excluded Values (m+5)/(mn+3m)

$\frac{m + 5}{m n + 3 m}$

Set the denominator in $\frac{m + 5}{m n + 3 m}$ equal to $0$ to find where the expression is undefined.

$m n + 3 m = 0$

Solve for $m$ .

Factor $m$ out of $m n + 3 m$ .

Factor $m$ out of $m n$ .

$m (n) + 3 m = 0$

Factor $m$ out of $3 m$ .

$m (n) + m \cdot 3 = 0$

Factor $m$ out of $m (n) + m \cdot 3$ .

$m (n + 3) = 0$

Divide each term in $m (n + 3) = 0$ by $n + 3$ and simplify.

Divide each term in $m (n + 3) = 0$ by $n + 3$ .

$\frac{m (n + 3)}{n + 3} = \frac{0}{n + 3}$

Simplify the left side.

Cancel the common factor of $n + 3$ .

Cancel the common factor.

$\frac{m (n + 3)}{n + 3} = \frac{0}{n + 3}$

Divide $m$ by $1$ .

$m = \frac{0}{n + 3}$

Simplify the right side.

Divide $0$ by $n + 3$ .

$m = 0$