Answers:
1) 3/4
2) 2a
3) 2a^2
4) a^5
5) 1
6) x = 8
7) When n = 0 then f(n) = 1
When n = 1 then f(n) = z
When n = 2 then f(n) = z^2
When n = 3 then f(n) = z^3
8) f(5) = 3 + 4 (5 - 1)
f(5) = 3 + 4 (4)
f(5) = 3 + 16
f(5) = 19
f(0) = 3 + 4 (0 - 1)
f(0) = 3 + 4 (-1)
f(0) = 3 + (-4)
f(0) = 3 - 4
f(0) = -1
9) 125
10) 1875