Question

Aflati ultima cifrav a nr c=76^20×67^30+45^21×39^22 repede!! dau 20 puncte

Answer 1

Explicație pas cu pas:

c=76^20×67^30+45^21×39^22

u(76)=6

u(6^k)= 6 => u( 6^ 20) =6 => u(76^20)=6

u (67)=7

u(7^k)=7 9 3 1 30 = 4×7 + 2 = multiplu de 4 + 2 =>

u(7^30)=9 => u(67^30)=9

u(76^20+67^30)=u(6+9)=5

u(45)=5

u(5^k)=5

u(45^21)=5

u(39)=9

u(9^k)= 9 1 22 =2× 11 22 este multiplu de 2

u(9^22)=1

u(39^22)=1

u(45^21+39^22)=u(5+1)=6

u(76^20×67^30+45^21×39^22)=u(5+6)=1