We are given the following expression
[tex]b^2-9a[/tex]Where the values of a and b are also given
a = 1/3
b = 9
Let us substitute these values into the given expression and then simplify the expression
[tex]\begin{gathered} b^2-9a \\ (9)^2-9(\frac{1}{3}) \\ (9\times9)-\frac{9}{3} \\ 81-3 \\ 78 \end{gathered}[/tex]Therefore, the expression is simplified to 78