What is the missing number in the table

Which of the following expressions are equivalent ?

You eat 8 strawberries and your friend eats 12 strawberries from a bowl. there are 20 strawberries left. which equation and solution give the original number of strawberries?

If f(x) = 4x – 3 and g(x) = 8x + 2, find each function value a.f[g(3)] b.g[f(5)] c.g{f[g(-4)]}