Đáp án:
Giải thích các bước giải:
`a)` `(7x-3)/(x-1)=2/3` `(ĐK:x\ne1)`
`↔(21x-9)/(3x-3)=(2x-2)/(3x-3)`
`→21x-9=2x-2`
`↔19x=7`
`↔x=7/19` (TMĐK)
Vậy `S={7/19}`
`b)` `(2(3-7x))/(x+1)=1/2(ĐK:x\ne-1)`
`↔(6-14x)/(x+1)=1/2`
`↔2(6-14x)=x+1`
`↔12-28x-x-1=0`
`↔11-29x=0`
`↔x=11/29` (TMĐK)
Vậy `S={11/29}`
`c)` `(5x-1)/(3x+2)=(5x-7)/(3x-1)(ĐK:x\ne-2/3;x\ne1/3)`
`↔((5x-1)(3x-1))/((3x+2)(3x-1))=((5x-7)(3x+2))/((3x-1)(3x+2))`
`→15x^2-8x+1=15x^2-11x-14`
`↔3x=-15`
`↔x=-5` (TMĐK)
Vậy `S={-5}`
`d)` `(4x+7)/(x-1)=(12x+5)/(3x+4)(ĐK:x\ne1;x\ne-4/3)`
`↔((4x+7)(3x+4))/((x-1)(3x+4))=((12x+5)(x-1))/((3x+4)(x-1))`
`→12x^2+37x+28=12x^2-7x-5`
`↔44x=-33`
`↔x=-3/4` (TMĐK)
Vậy `S={-3/4}`
