Question

aflati ultima cifra a nr a=4^43-3^34​

Answer 1

$U(4^{43}-3^{34})=\\ \\ =U(4^{42}\cdot 4 - 3^{36}:3^2)\\ \\ = U(16^{21}\cdot 4-81^{9}:9)\\ \\ =U(6\cdot 4-81^8\cdot 81:9)\\ \\ = U(24-1\cdot 81:9)\\ \\ = U(24-9)\\ \\ = U(15)\\ \\ = \boxed{5}$

Answer 2

Răspuns:

uc(a) = 5

Explicație pas cu pas:

Notatie: uc(a) = ultima cifra a numarului a

uc (a) = ? ; a = 4⁴³ - 3³⁴

uc (a) = uc (4⁴³)- uc (3³⁴)

uc(4¹)= 4 ; uc(4²) = 6

43 = 21 x 2 + 1 =>

uc(4⁴³) = uc(4¹) = 4

uc(3¹) = 3 ; uc(3²) = 9 ; uc(3³) = 7 ; uc(3⁴) = 1

34 = 8 x 4 + 2 => uc(3³⁴) = uc(3²) = 9

uc(a) = uc(4-9) =  5

uc(a) = 5