Problem Solving (PS) | Re: If m = 7^20 +7^21 +7^22, what is the largest prime factor of m?

If m = 7^20 + 7^21 + 7^22, what is the largest prime factor of m?

A. 3
B. 7
C. 13
D. 17
E. 19

m = 7^20(1+7+49) = 7^20* 57 = 7^20*3*19

Largest prime factor = 19 - Answer - E

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