- #1
buzzmath
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Could someone please give me some advice on solving these problems
1. find the last digit of the decimal expansion 7^999999?
I think i have to do something like 7^999999(mod10) but I'm not really sure if that's right or how i would do that
2. Show that every positive integer relatively prime to 10 divides infinitely many repunits? I don't know what a repunit is or how i would even begin this problem.
Thanks
1. find the last digit of the decimal expansion 7^999999?
I think i have to do something like 7^999999(mod10) but I'm not really sure if that's right or how i would do that
2. Show that every positive integer relatively prime to 10 divides infinitely many repunits? I don't know what a repunit is or how i would even begin this problem.
Thanks