Prove by math induction that 7*(3n+1)-1 is divisible by 9.

Question

Prove by math induction that 7*(3n+1)-1 is divisible by 9.

Answer 1

It is not true, as stated. Here is a counterexample: n = 2

7(3n + 1) - 1 = 7[3(2) + 1] - 1 = 7(7) -1 = 48

48 is not divisible by 9.