Answer:
a = 4
Step-by-step explanation:
We can set up an equation to model this:
a = [tex]\frac{k}{b^2}[/tex]
Now, we can plug in the information given to find the value of k:
9 = [tex]\frac{k}{2^2}[/tex]
9 = [tex]\frac{k}{4}[/tex]
36 = k
Now, we can find the value of a when b = 3.
a = [tex]\frac{36}{3^2}[/tex]
a = [tex]\frac{36}{9}[/tex]
a = 4