Answer
$\frac{1}{4}$
Work Step by Step
$\frac{3}{x}\div\frac{12}{x}$
Invert the divisor and multiply.
$\frac{3}{x}\times\frac{x}{12}$
Eliminate common factors.
$\frac{\big/\!\!\!3}{\big/\!\!\!x}\times\frac{\big/\!\!\!x}{\big/\!\!\!3\times4}$
Multiply numerator by numerator and denominator by denominator.
$\frac{1}{4}$
