Question: prove by mathematical induction that for ngt1 n ...
prove by mathematical induction that for n>=1 , n : integer
a) (11^n) -1 is a multiple of 10
b) (5^n) + 3 is divisible by 4
c) (5^2n) - 1 is a multiple of 8
d) (9^n) - 3 is a multiple of 6
e) (n^2) + 2n is divisible by 8
f) (3^n) + (7^n) is divisible by 10