Find the Excluded Values (x^2-16)/(4x+5)

$\frac{x^{2} - 16}{4 x + 5}$

Set the denominator in $\frac{x^{2} - 16}{4 x + 5}$ equal to $0$ to find where the expression is undefined.

$4 x + 5 = 0$

Solve for $x$ .

Subtract $5$ from both sides of the equation.

$4 x = - 5$

Divide each term in $4 x = - 5$ by $4$ and simplify.

Divide each term in $4 x = - 5$ by $4$ .

$\frac{4 x}{4} = \frac{- 5}{4}$

Simplify the left side.

Cancel the common factor of $4$ .

Cancel the common factor.

$\frac{4 x}{4} = \frac{- 5}{4}$

Divide $x$ by $1$ .

$x = \frac{- 5}{4}$

Simplify the right side.

Move the negative in front of the fraction.

$x = - \frac{5}{4}$