Đáp án:

 

Giải thích các bước giải:

`a.`

`(x - 1)/3 = (x -2)/2`

`=> 2(x - 1) = 3(x-2)`

`=> 2x - 2 = 3x - 6`

`=>2x - 3x = -6 + 2`

`=> -x = -4`

`=>x = 4`

Vậy `x =4`

`b.`

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

`=> 6(1 - 2x ) = 4(5 + x)`

`=> 6 - 12x = 20 + 4x`

`=> -12x - 4x = 20 - 6`

`=> - 16x = 14`

`=> x = 14 :(-16)`

`=>x = -7/8`

Vậy `x =-7/8`

`c.`

`(7x + 5)/7 = (6x - 5)/14`

`=>14(7x + 5) = 7( 6x - 5)`

`=> 6x - 5 = 2(7x + 5)`

`=> 6x - 5 = 14x + 10`

`=> 6x - 14x = 10 + 5`

`=> -8x = 15`

`=>x =-15/8`

Vậy `x =-15/8`

`d.`

`x/3 - (2x + 1)/4 = (5x )/6 - x`

`=> ( 4x )/12 - (3(2x + 1 ))/12 = (10x )/12 - (12x)/12`

`=> 4x - 6x - 3 = 10x - 12x`

`=> -2x - 3 = -2x`

`=> -2x + 2x = 3`

`=> 0=3 (vô \lý)`

Vậy `x in \emptyset`

`~nhungan~`