In order to find the missing values of f(5) and g(3), we have to use the piecewise functions, for that we look at the intervals for f(x) and g(x) where 5 and 3 are ubicated respectively.
for f(5), 5 lies on the interval x≥3.
then,

for g(3), 3 lies on the interval x>-2.

After the corresponding values are found the expression can be writen as

The correct answer is 28.