Đáp án + Giải thích các bước giải:
Tìm `x:`
`a)` `3/4 - x + 6/(-11) = 5/6`
`3/4 - x = 5/6 - (-6)/11`
`3/4 - x = 5/6 + 6/11`
`3/4 - x = 55/66 + 36/66`
`3/4 - x = 91/66`
`x = 3/4 - 91/66`
`x = 99/132 + (-182)/132`
`x = (-83)/132`
Vậy `x = (-83)/132`
`b)` `x + 5/6 = (-3)/4`
`x = (-3)/4 - 5/6`
`x = (-9)/12 + (-10)/12`
`x = (-19)/12`
Vậy `x = (-19)/12`
`c)` `5/12 + 5/x - 1/8 = 1/2`
`5/12 + 5/x = 1/2 + 1/8`
`5/12 + 5/x = 4/8 + 1/8`
`5/12 + 5/x = 5/8`
`5/x = 5/8 - 5/12`
`5/x = 15/24 + (-10)/24`
`5/x = 5/24`
`=>` `x = 24`
Vậy `x = 24`
`d)` `x - 4/3 = 4/5`
`x = 4/5 + 4/3`
`x = 12/15 + 20/15`
`x = 32/15`
Vậy `x = 32/15`
`e)` `x + 1/9 - 3/5 = 3/6`
`x + 1/9 = 3/6 + 3/5`
`x + 1/9 = 15/30 + 18/30`
`x + 1/9 = 11/10`
`x = 11/10 - 1/9`
`x = 99/90 + (-10)/90`
`x = 89/90`
Vậy `x = 89/90`
`f)` `11/4 - x = 5/7`
`x = 11/4 - 5/7`
`x = 77/28 + (-20)/28`
`x = 57/28`
Vậy `x = 57/28`
`g)` `x/4 - 3/7 + 2/5 = 31/140`
`x/4 - 3/7 = 31/140 - 2/5`
`x/4 - 3/7 = 31/140 + (-56)/140`
`x/4 - 3/7 = (-5)/28`
`x/4 = (-5)/28 + 3/7`
`x/4 = (-5)/28 + 12/28`
`x/4 = 1/4`
`=> x = 1`
Vậy `x = 1`
`h)` `4/9 + x = (-2)/5`
`x = (-2)/5 - 4/9`
`x = (-18)/45 + (-20)/45`
`x = (-38)/45`
Vậy `x = (-38)/45`
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