Establish the order of growth:

1) . x(n) = x(n 1) + 5 for n > 1, x(1) = 0

2) . x(n) = 3x(n 1) for n > 1, x(1) = 4

3) . x(n) = x(n 1) + n for n > 0, x(0) = 0.