Question

Explain why the number 7^20+7^21+7^22 could not be prime

Answer 1

cause its chock full of multiplication for starters :)

Answer 2

but thats prolly not why

Answer 3

:o

Answer 4

At first I thought it was some great number theory with mods/fermat's little theorem etc, but it isn't:/

7^20+7^21+7^22 = 7(7^19 + 7^20 + 7^22) = ab where a,b > 1 so is not prime

Answer 5

Thank You . ( :

Answer 6

i knew it..... there was a multiplication involved lol