`a)`

`(5x-4)/2 = (16x+1)/7`

`7.(5x-4)=2.(16x+1)`

`35x-28=32x+2`

`35x-32x=2+28`

`3x=30`

`x=10`

Vậy `S={10}`.

`b)`

`(12x+5)/3 = (2x-7)/4`

`4.(12x+5)=3.(2x-7)`

`48x+20=6x-21`

`48x-6x=-21-20`

`42x=-41`

`x=(-41)/42`

Vậy `S={(-41)/42}`.

`c)`

`(3x-8)/12 = (5-x)/8`

`2.(3x-8)=3.(5-x)`

`6x-16=15-3x`

`6x+3x=15+16`

`9x=31`

`x=31/9`

Vậy `S={31/9}`.

`d)`

`(5x+16)/15 = (x-4)/10`

`10.(5x+16)=15.(x-4)`

`50x+160=15x-60`

`50x-15x=-60-160`

`35x=-220`

`x=(-44)/7`

Vậy `S={(-44)/7}`.