Question

[ggggggxf]

Tính : B = 2/1x3 + 2/3x5 + 2/5x7 + 2/7x9 + ..... + 2/99x101

Answer 1

[나 재민]

\(B=\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{99.101}\)

\(\Rightarrow B=1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{99}-\frac{1}{101}\)

\(\Rightarrow B=1-\frac{1}{101}=\frac{101}{101}-\frac{1}{101}=\frac{100}{101}\)

_Học tốt_

Answer 2

[Nguyễn Việt Duy]

100/101