Answer
$\frac{4x}{x+5}$
Work Step by Step
Factor each term then eliminate any factors that are common to numerators and denominators.
Multiply numerator by numerator and denominator by denominator.
$\frac{x}{3}\times\frac{12}{x+5}=\frac{x}{\big/\!\!\!3}\times\frac{\big/\!\!\!3\times4}{x+5}=\frac{4x}{x+5}$