\(\frac{1}{99.100}-\frac{1}{98.99}-\frac{1}{97.98}-...-\frac{1}{15.16}\)
\(=\frac{1}{99.100}-\left(\frac{1}{15.16}+\frac{1}{16.17}+...+\frac{1}{97.98}+\frac{1}{98.99}\right)\)
\(=\frac{1}{9900}-\left(\frac{1}{15}-\frac{1}{16}+\frac{1}{16}-\frac{1}{17}+...+\frac{1}{97}-\frac{1}{98}+\frac{1}{98}-\frac{1}{99}\right)\)
\(=\frac{1}{9900}-\left(\frac{1}{15}-\frac{1}{99}\right)\)
\(=\frac{1}{9900}-\frac{28}{495}=-\frac{559}{9900}\)
=\(\frac{559}{9900}\)
k mk nha bn
dù ko nhanh nhất nhưng
mong bn ủng hộ mk nha!