5^284 mod 7 using Fermat's Little TheoremSolution:`5^(284) ("mod "7)`
Fermat's Little Theorem
`a^(p-1)-=1 ("mod "p)` (where `p` is prime, `a` is not divisible by `p`)
Step-1: Identify conditions :`p=7` is prime.
`a=5` is not divisible by `p=7`.
So, Apply the theorem
`5^(7-1)-=1 ("mod "7)`
`5^(6)-=1 ("mod "7)`
Step-2: Reduce the exponent `284``284-:6=47` with a remainder of `2`
i.e., `284=6xx47+2`
Step-3: SimplifyWe have
`5^(6)-=1 ("mod "7)`
Taking power `47` on both sides
`(5^(6))^47-=1^47 ("mod "7)`
`5^((6xx47))-=1 ("mod "7)`
Multiply by `5^2` on both sides
`5^((6xx47))xx5^2-=1xx5^2 ("mod "7)`
`5^((6xx47)+2)-=5^2 ("mod "7)`
`5^(284)-=25 ("mod "7)`
`5^(284)-=4 ("mod "7)`
`:.` The remainder is `4` when you divide `5^(284)` by `7`
This material is intended as a summary. Use your textbook for detail explanation.
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