Đáp án:
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`b,`
`7/4 - (x + 5/3) = (-12)/5`
`↔ x + 5/3 = 7/4 - (-12)/5`
`↔x + 5/3 = 35/20 + 48/20`
`↔x + 5/3 = 83/20`
`↔ x = 83/20 - 5/3`
`↔x=249/60 - 100/60`
`↔ x = 149/60`
Vậy `x=149/60`
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`d,`
`2/3 + 7/4 ÷ x =5/6`
`↔ 7/4 ÷ x =5/6 - 2/3`
`↔ 7/4 ÷ x= 5/6 - 4/6`
`↔ 7/4 ÷ x = 1/6`
`↔x=7/4 ÷ 1/6`
`↔x=7/4 × 6`
`↔x=21/2`
Vậy `x=21/2`
