Question: 6n+2+72n+1 is divisible by 43?
Answer: 6n+2+72n+1 is divisible by 43. Since both forms in this sum are divisible by 43(the first because it is 43 times an integer and the second by the assumption of the induction step), it follows that 6k+2−72k+1 is also divisible of 43. Thus, by the principle of mathematical induction, 6n+2—72n+1 is a divisible of 43.