`A = 49 8/23 - (5 7/32 + 14 8/23)`
`= 49 8/23-5 7/32-14 8/23`
`= (49 8/23 - 14 8/23) -5 7/32`
`= 35 - 5 7/32`
`= 29 25/32`
`B= 71 38/45 - (43 8/45 - 1 17/57)`
`= 71 38/45 - 43 8 /45 + 1 17/57`
`= ( 71 38/45 - 43 8 /45 )+ 1 17/57`
`= 28 2/3 + 1 17/57 `
`= 29 55/57 `
`C= (-3)/7 * 5/9 + 4/9 * (-3)/7 + 2 3/7 `
`= (-3)/7 *( 5/9 + 4/9 ) + 2 3/7 `
`= (-3)/7 + 2 3/7 `
`=2`