Question

A=5/1.3+5/3.5+5/5.7+...+5/99.101

Answer 1

A=5/1.3+5/3.5+5/5.7+...+5/99.101

A=5.1/2 [1/1-1/3+1/3-1/5+1/5-1/7+1/7+...+1/99-1/101 ]

A=5.1/2.100/101

A=250/101

k  nha

Answer 2

thế bn tạo câu hỏi này ra làm j?

k bn thì ......!

ko hiểu nổi<☻>

Answer 3

\(A=\frac{5}{1.3}+\frac{5}{3.5}+\frac{5}{5.7}+...+\frac{5}{99.100}\)

\(A=5:2\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+...+\frac{1}{99}-\frac{1}{100}\right)\)

\(A=2,5\left(1-\frac{1}{100}\right)\)

\(A=2,5.\frac{99}{100}=\frac{99}{40}\)