Question

Determinați ultima cifră a numărului x=12^200 + 23^201 + 34^302 + 45^403.
Dau 10 puncte.

Answer 1

x = 12^200 + 23^201 + 34^302 + 45^403

U(12^200) = U ( 2^200) = U ( 2^4) = U ( 16) = 6

U( 23^201) = U ( 3^201) = U (3^1) = 3

U ( 34^302) = U(4^302) = U ( 4^2) = U(16) = 6

U (45^403) = U (5^403) = 5


U ( x ) = U ( 6 + 3 + 6 + 5) = U ( 20) = 0
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