Đáp án:
`A=30(25)/32`
`B=29(55)/57`
`C=2`
`D=306/35`
Giải thích các bước giải:
`A=49(8)/23-(5(7)/32+14(8)/23)`
`=48(8)/23-14(8)/23-5(7)/32`
`=35-5(7)/32`
`=35(32)/32-5(7)/32`
`=30(25)/32`
`B=71(38)/45-(43(8)/45-1(17)/57)`
`=71(38)/45-43(8)/45+1(17)/57`
`=28(30)/45 + 1(17)/57`
`=28(38)/57+1(17)/57`
`=29(55)/57`
`C=(-3)/7 . 5/9+4/9.(-3)/7+2(3)/7`
`=(-3)/7.(5/9 + 4/9)+ 17/7`
`=(-3)/7 .1+17/7`
`=14/7=2`
`D=(19(5)/8:7/12-13(1)/4:7/12). 4/5`
`=(19(5)/8. 12/7 -13(1)/4. 12/7). 4/5`
`=12/7(19(5)/8-13(2)/8). 4/5`
`=12/7 . 51/8 . 4/5`
`=306/35`