m = 2/3.5 + 2/5.7 + 2/7.9 + .... + 2/97.99
m= 1/3 - 1/5 + 1/5 - 1/7 + 1/95 - 1/97 + 1/97 - 1/99
m = 1/3 - 1/99
m = 32/99
M= \(\frac{2}{3.5}\) + \(\frac{2}{5.7}\) + \(\frac{2}{7.9}\) + ... + \(\frac{2}{97.99}\)
M= \(\frac{1}{3}\) - \(\frac{1}{5}\) + \(\frac{1}{5}\) - \(\frac{1}{7}\) + \(\frac{1}{7}\) - \(\frac{1}{9}\)+ ...+\(\frac{1}{97}\) - \(\frac{1}{99}\)
M= \(\frac{1}{3}\) - \(\frac{1}{99}\)
M=\(\frac{32}{99}\)
k cho mình nha!
Ta có :
\(M=\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{97.99}\)
\(=1.\left(\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{97.99}\right)\)
\(=1.\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-...+\frac{1}{97}-\frac{1}{99}\right)\)
\(=1.\left(\frac{1}{3}-\frac{1}{99}\right)\)
\(=1.\frac{32}{99}\)
\(=\frac{32}{99}\)
M = 2 / 3 . 5 + 2 / 5 . 7 + 2 / 7 .9 +.... + 2 / 97 . 99
M = 1 / 3 - 1 / 5 + 1 / 5 - 1 / 7 + 1 / 7 - 1 / 9 + ..+ 1 /97 - 1 / 99
M = 1 / 3 - 1 / 99
M = 33 / 99 - 1 / 99
M = 32 / 99
