Question

[Diệu Hồng Ánh Nguyễn]

1/10 + 2/10 + 3/10+ 4/10 + 5/10 + 6/10 + 7/10 + 8/10 + 9/10 =?

Answer 1

[Hquynh]

\(\dfrac{1}{10}+\dfrac{2}{10}+\dfrac{3}{10}+\dfrac{4}{10}+\dfrac{5}{10}+\dfrac{6}{10}+\dfrac{7}{10}+\dfrac{8}{10}+\dfrac{9}{10}=\dfrac{1}{10}.\left(1+2+3+4+5+6+7+8+9\right)\\ =\dfrac{1}{10}.45=\dfrac{45}{10}=\dfrac{45:5}{10:5}=\dfrac{9}{2}\)

Answer 2

[Nguyễn Lê Phước Thịnh]