Câu hỏi của Nhìn là điên

Question

5/4×7+5/7×10+5/10×13+........+5/97×100

QuocDat · Accepted Answer

$\frac{5}{4.7}+\frac{5}{7.10}+\frac{5}{10.13}+...+\frac{5}{97.100}$

$=5\left(\frac{1}{4.7}+\frac{1}{7.10}+\frac{1}{10.13}+...+\frac{1}{97.100}\right)$

$=5.\frac{1}{3}\left(\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+\frac{1}{10}-\frac{1}{13}+...+\frac{1}{97}-\frac{1}{100}\right)$

$=\frac{5}{3}\left(\frac{1}{4}-\frac{1}{100}\right)$

$=\frac{2}{5}$

Câu trả lời:

$\frac{5}{4.7}+\frac{5}{7.10}+\frac{5}{10.13}+...+\frac{5}{97.100}$

$=5\left(\frac{1}{4.7}+\frac{1}{7.10}+\frac{1}{10.13}+...+\frac{1}{97.100}\right)$

$=5.\frac{1}{3}\left(\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+\frac{1}{10}-\frac{1}{13}+...+\frac{1}{97}-\frac{1}{100}\right)$

$=\frac{5}{3}\left(\frac{1}{4}-\frac{1}{100}\right)$

$=\frac{2}{5}$

Nhìn là điên · Answer

thank you

Câu trả lời:

thank you