Answer :
Given:
A serving of a frozen casserole is 1/4 of a pan.
Vicky has 1/9 of the pan.
[tex]\begin{gathered} \frac{1}{4}(x)=\frac{1}{9} \\ \text{Multiply by 4 on both sides} \\ 4\cdot\frac{1}{4}x=4\cdot\frac{1}{9} \\ x=\frac{4}{9} \end{gathered}[/tex]Answer: Vicky has eaten 4/9 of a serving.