Answer:

Step-by-step explanation:
The base case in the recursive function are:


The recursive case is equal to:

So replace
for
:

In the new expression
is a base case so you don't have to worry for that part, but
is still the recursive case so evaluate again in 

and
are define as base cases so you replace for it's numbers:

Now return to
and replace for the new values:

So the final answer is 20
21/7 + 3/7(3x - 5) = -4
21/7 + 9/7x - 15/7 = -4.....multiply everything by 7
21 + 9x - 15 = - 28
9x + 6 = -28
9x = -28 - 6
9x = - 34
x = -34/9 or - 3 7/9
Its called the median
hope this helps you