Đáp án:
Giải thích các bước giải:
`A=(13/5-32/9):(73/21-10/7)`
`= (\frac{13.9-32.5}{5.9}) :( \frac{73-10.3}{21})`
`= (\frac{-43}{45}):\frac{43}{21}`
`=(\frac{-43}{45}).\frac{21}{43}`
`= \frac{-7}{15}`
Cách 1:
`B=7/2+135/9:26/7-22/9:26/7`
`= 7/2 + 135/9 . 7/26 -22/9 . 7/26`
`= 7/2 + \frac{105}{26} -\frac{77}{117}`
`= \frac{7.117}{2.117}+ \frac{105.9}{26.9}-\frac{77.2}{117.2}`
`=\frac{1610}{234}`
`=\frac{805}{117}`
Cách 2:
`B=7/2+135/9:26/7-22/9:26/7`
`= 7/2 + 135/9 . 7/26 -22/9 . 7/26`
`= 7/2 + \frac{7}{26} .( 135/9 -22/9)`
`= 7/2 + 7/26 . 113/9`
`= 7/2 + 791/234`
`= \frac{7.117}{2.117} +\frac{791}{234}`
`= \frac{819}{234} +\frac{791}{234}`
`= \frac{1610}{234}`
`= \frac{805}{117}`
