Question

TÍNH

K = \(\frac{1}{1.3}+\frac{1}{3.5}+...........+\frac{1}{47.49}\)

 

 

Answer 1

\(K=\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{47.49}\)

    \(=2\left(\frac{1}{1.3}+\frac{1}{3.5}+...+\frac{1}{47.49}\right):2\)

     =  \(\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{47}-\frac{1}{49}\right):2\)   

     = \(\left(1-\frac{1}{49}\right):2\)

     \(=\frac{48}{49}:2\) \(\frac{24}{49}\)

 

Answer 2

\(\frac{48}{49}\)

Answer 3

\(K=\frac{1}{2}\left(\frac{1}{3}-\frac{1}{5}+....+\frac{1}{47}-\frac{1}{49}\right)=\frac{1}{2}.\frac{46}{147}=\frac{23}{147}\)