Răspuns:
a.(1+2+3+......+2018)÷2019
(2018×2019/2)÷2019
(1009×2019)÷2019
2037171÷2019
1009
b.2×(1+2+3+....+2019)÷2020
2×(2019×2020/2)÷2020
2×(2019×1010)÷2020
2×2039190÷2020
4078380÷2020
2019
Explicație pas cu pas:
e suma lui gaus