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Use mathematical induction to prove that 64 divides 3^(2n+2) + 56n + 55 for every positive integer n.

User Kkpattern
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Final answer:

The statement can be proven using mathematical induction. We prove the base case and then use the inductive hypothesis to prove the inductive step. By rearranging terms and factoring out a common factor, we show that the expression is divisible by 64. Therefore, the statement holds for every positive integer n.

Step-by-step explanation:

We will prove the statement using mathematical induction.

Base case: For n = 1, we have:
3^(2(1)+2) + 56(1) + 55 = 3^4 + 56 + 55 = 81 + 56 + 55 = 192.

Since 192 is divisible by 64, the statement holds for n = 1.

Inductive step: Assume the statement holds for some value of n: 3^(2n+2) + 56n + 55 is divisible by 64.

We need to prove the statement holds for n = k+1:

3^(2(k+1)+2) + 56(k+1) + 55 = 3^(2k+4) + 56k + 111.

Using the inductive hypothesis, we can write this expression as:
(3^2 * 3^(2k+2)) + 56k + 111.

By rearranging terms, we have:
(9 * 3^(2k+2)) + 56k + 111.

Factoring out 9, we get:
9 * (3^(2k+2) + (56k + 111)/9).

Since the second term is an integer (56k + 111) divided by 9, we can replace it with another integer without affecting the divisibility by 64.

Therefore, we have:
9 * (3^(2k+2) + m), where m is an integer.

Thus, the expression is divisible by 64.

Hence, by mathematical induction, we have proved that 64 divides 3^(2n+2) + 56n + 55 for every positive integer n.

User Piks
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