Variable $x$ cannot be equal to $4$ since division by zero is not defined. Multiply both sides of the equation by $5\left(x-4\right)$, the least common multiple of $x-4,5$.
$$5\left(x+4\right)=4\left(x-4\right)$$
Use the distributive property to multiply $5$ by $x+4$.
$$5x+20=4\left(x-4\right)$$
Use the distributive property to multiply $4$ by $x-4$.
