Answer
$\frac{81}{36x}$
Work Step by Step
$\frac{9}{4x}= \frac{}{36x}$
First, compare the denominators:
$36x \div 4x =9$
The denominator of the second fraction is 9 times greater than the first fraction. The numerator of the second fraction must therefore also be 9 times greater than the first fraction, since the two fractions are equal. So, multiplying the first numerator by 9 gives:
$9\times 9= 81$
So, $\frac{9}{4x}= \frac{81}{36x}$
