Đáp án + giải thích bước giải :
`A = 49 8/23 - (5 7/32 + 14 8/23)`
`-> A = 49 8/23 - 5 7/32 - 14 8/23`
`-> A = (49 8/23 - 14 8/23) - 5 7/32`
`-> A = 35 - 167/32`
`-> A = 953/32`
`B = 71 38/45 - (43 8/45 - 1 17/57)`
`-> B = 71 38/45 - 43 8/45 + 1 17/57`
`-> B = 28 30/45 + 1 17/57`
`-> B = 1290/45 + 74/57`
`-> B =1708/57`
`C = (-3)/7 . 5/9 + 4/9 . (-3)/7 + 2 3/7`
`-> C = (-3)/7 . (5/9 + 4/9) + 2 3/7`
`-> C = (-3)/7 + 17/7`
`-> C = 14/7`
`D = (19 5/8 : 7/12 - 13 1/4 : 7/12) . 4/5`
`-> D = (157/8 . 12/7 - 53/4 . 12/7) . 4/5`
`-> D = 153/14 . 4/5`
`-> D = 306/35`
