Sai đề nhé, phải là:
`\frac{3}{4}` `.` `\frac{8}{9}` `.` `\frac{15}{16}` `...` `\frac{9999}{10000}`
`=` `\frac{3.8.15...9999}{4.9.16...10000}`
`=` `\frac{(1.3).(2.4).(3.5)...(99.101)}{(2.2).(3.3).(4.4)...(100.100)}`
`=` `\frac{(1.2.3...99).(3.4.5...101)}{(2.3.4...100).(2.3.4...100)}`
`=` `\frac{1.101}{100.2}`
`=` `101/200`
@ced