Question

a = 2018^2019+ 2019^2018+ 2020^2015+ 2015^2012+ 2016^2016
u.c (a) =?

u.c= ultima cifră
^ = la puterea

Answer 1

a = 2018^2019+ 2019^2018+ 2020^2015+ 2015^2012+ 2016^2016

Uc(2018^2019) = Uc(8^3) = Uc (512) = 2

Uc(2019^2018) = Uc(9^2018) = 1

2018 este putere para si stim ca 9 la o putere para are ultima cifra 1, iar 9 la o putere impara are ultima cifra 9)

Uc(2020^2015) = 0

Uc(2015^2012) = Uc(5^2012) = 5

( 5 la orice putere are ultima cifra 5)

Uc(2016^2016) = Uc(6^2016) = 6

(6 la orice putere are ultima cifra 6)
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Uc ( a ) = Uc ( 2 + 1 + 0 + 5 + 6) = Uc ( 14) = 4
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