Question

thực hiện phép tính sau 

M=1/3+1/15+1/35+...+1/2499

Answer 1

\(M=\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{49.51}\)

\(M=\frac{1}{2}\left(1-\frac{1}{51}\right)\)

M=\(\frac{1}{2}.\frac{50}{51}=\frac{25}{51}\)

Answer 2

\(M=\frac{1}{3}+\frac{1}{15}+\frac{1}{35}+...+\frac{1}{2499}\)

\(M=\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{49.51}\)

\(M=\frac{1}{2}.\left(\frac{1}{1}-\frac{1}{3}+...+\frac{1}{49}-\frac{1}{51}\right)\)

\(M=\frac{1}{2}.\left(\frac{1}{1}-\frac{1}{51}\right)\)

\(M=\frac{1}{2}.\frac{50}{51}\)

\(M=\frac{25}{51}\)

Answer 3

M=\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{49.51}\)

M=\(\frac{1}{2}.\left(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{49.51}\right)\)

M=\(\frac{1}{2}.\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{49}-\frac{1}{51}\right)\)

M=\(\frac{1}{2}.\left(\frac{1}{1}-\frac{1}{51}\right)\)

M=\(\frac{1}{2}.\frac{50}{51}\)

M=\(\frac{25}{51}\)

( k mình nha)