giúp mình đi mà chỉ 2 câu thôi

`a)`

`{5(x-1)+2}/{6}-{7x-1}/{4}={2(2x+1)}/{7}-5`

`<=>{5x-3}/{6}-{7x-1}/{4}={4x-33}/{7}`

`<=>{14(5x-3)}/{84}-{21(7x-1)}/{84}={12(4x-33)}/{84}`

`<=>14(5x-3)-21(7x-1)=12(4x-33)`

`<=>70x-42-147x+21=48x-396`

`<=>125x=375`

`<=>x=3` 

Vậy `S={3}`

`b)`

`{3(x-3)}/{4}+{4x-10,5}/{10}={3(x+1)}/{5}+6`

`<=>``{15(x-3)}/{20}+{2(4x-10,5)}/{20}={12(x+1)}/{20}+{6.20}/{20}`

`<=>15(x-3)+2(4x-10,5)=12(x+1)+6.20`

`<=>15x-45+8x-21=12x+12+120`

`<=>15x-45+8x-21-12x-12-120=0`

`<=>11x=198`

`<=>x=18` 

Vậy `S={18}`