Okay, here we have this:
Considering the provided fraction, we are going to rewrite it as equivalent fraction with the given denominator, so we obtain the following:
Then we will solve the following proportion to find the missing value:
[tex]\frac{3}{4}=\frac{x}{12}[/tex]Solving for x:
[tex]\begin{gathered} x=\frac{3}{4}\cdot12 \\ x=\frac{36}{4} \\ x=9 \end{gathered}[/tex]Finally we obtain the following fractions:
[tex]\frac{3}{4}=\frac{9}{12}[/tex]