Question

TÍNH:

M=\(\frac{6}{1.3}\)+\(\frac{6}{3.5}\)+\(\frac{6}{5.7}\)+...,...+\(\frac{6}{49.51}\)

Answer 1

=3(1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+..+1/49-1/51)

=3x50/51=50/17

theo tôi là thế còn các bn

Answer 2

M = \(3\left(\frac{2}{1\cdot3}+\frac{2}{3\cdot5}+...+\frac{2}{49\cdot51}\right)\)\(=3\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{49}-\frac{1}{51}\right)\)

M = \(3\left(1-\frac{1}{51}\right)=3\cdot\frac{50}{51}=\frac{50}{17}\)