If you replace the varaibles you will get:
\(\frac{1}{3}(3^2)+5.2(2)\)
First complete: \(\frac{1}{3}(3^2)\)
\(\frac{1*3^2}{3}\)
\(\frac{3^2}{3}\)
\(3\)
Then complete: \(5.2(2)\)
\(5.2(2)\)
\(10.4\)
Now you have:
\(3+10.4\)
\(13.4\)
Your answer is 13.4
Hope this Helps ;P