Question

[nguyễn thị minh sang]

B= \(\dfrac{2}{1.4}+\dfrac{2}{4.7}+\dfrac{2}{7.9}+...+\dfrac{2}{100.103}\)

Answer 1

[Nguyễn Gia Khánh]

\(\dfrac{3}{2}\)B= \(\dfrac{3}{1.4}+\dfrac{3}{4.7}+\dfrac{3}{7.10}+...+\dfrac{3}{100.103}\)

\(\dfrac{3}{2}\)B= \(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{10}+...+\dfrac{1}{100}-\dfrac{1}{103}\)   \(\dfrac{3}{2}\)B= \(\dfrac{102}{103}\)   \(\)B= \(\dfrac{102}{103}:\dfrac{3}{2}\)   B=\(\dfrac{68}{103}\)

Answer 2

[Hoàng Bảo Linh]

68/103