use the method of repeated substitution to solve for recurrence. then prove the answer is correct by induction.

3. A student counted up the number of statements executed in a program developed for sorting n integers and came up with a recurrence of the form: T(n) = a * n + b + T(n-1), and T(1) = s where a, b and s are constants. (a) [10] Use the method of repeated substitution to solve this recurrence. formula are not permitted. (b) 10] Prove your answer to (a) is correct by induction