recurrence relations

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7. Solve the following recurrences and find the efficiency class for each of them. (10%) 1. A(n) = 3A(n-1) for n > 1, A(1) = 4 2. A(n) = A(n-1) + 5 for n > 1, A(1) = 0 3. A(n) = A(n 1) + n for n > 0, A(0) = 0 4. A(n) = A(n/5) + 1 for n > 1, A(1) = 1 (solve for n = 5k)