Question

Aflați ultima cifră a numărului:
a) 3²⁰¹⁹+5²⁰²⁰+1²⁰²¹;
b) 2²⁰¹⁹+6²⁰²⁰+2019⁰
c) 4²⁰¹⁹+7²⁰²⁰+8²⁰²¹-9²⁰²²



repede plssssss dau coroană și 40 de puncte​

Answer 1

Răspuns:

a) 3¹=3 ; 3²=9; 3³=27; 3⁴=81 ; 3⁵=..3

2019:4=504 rest 3

3²⁰¹⁹=...7

5¹=5 ; 5²=25; 5³=...5

5²⁰²⁰=...5

1²⁰²¹=1

7+5+1=13

ultima cifra a 3²⁰¹⁹+5²⁰²⁰+1²⁰²¹ = 3

b) 2¹=2; 2²=4; 2³=8; 2⁴=16; 2⁵=32; 2⁶=..4

2019:4=504 rest 3

2²⁰¹⁹=....8

6¹=6; 6²=36; 6³=...6

6²⁰²⁰=...6

2019⁰=1

8+6+1=15

ultima cifra a 2²⁰¹⁹+6²⁰²⁰+2019⁰ = 5

c) 4¹=4; 4²=16; 4³=64; 4⁴=...6

2019:2=1009 rest 1

4²⁰¹⁹=....4

7¹=7; 7²=49; 7³= ...3; 7⁴=..1; 7⁵=...7

2020:4=505 rest 0

7²⁰²⁰=...1

8¹=8; 8²=64; 8³=...2; 8⁴=...6; 8⁵=...8

2021:4=505 rest 1

8²⁰²¹=...8

9¹=9; 9²=81; 9³=...9; 9⁴=...1

2022:2=1011 rest 0

9²⁰²²=...9

4+1+8-9=4

ultima cifra a 4²⁰¹⁹+7²⁰²⁰+8²⁰²¹-9²⁰²² =5

Sper ca te-am ajutat!