Answer:

Explanation:
Given

Required
Write an equivalent expression in C
The given expression uses + and + is represented as + in C
So: The equivalent expression is

However, C supports compound assignment operators
So:
can be rewritten as

Answer:
See Explanation
Explanation:
Given
The attached function
What the recursion does is that; it adds up individual digits from N to 0
Solving (a): Each output when N = 6
For N = 6.
The function returns the following values:
f(6) = 6
Then: 6 + f(5)
Then: 6 + 5 + f(4)
Then: 6 + 5 + 4 + f(3)
Then: 6 + 5 + 4 + 3 + f(2)
Then: 6 + 5 + 4 + 3 + 2 + f(1)
Then: 6 + 5 + 4 + 3 + 2 + 1 + f(0)
Then: 6 + 5 + 4 + 3 + 2 + 1 + 0 = 21
Solving (b): The output when N = 7
Using the same process in (a) above.
The output is 28