`a)``x/3-(5x)/6-(15x)/(12)=x/4-5`
`<=>(4x-10x-15x)/(12)=(3x-60)/(12)`
`<=>-21x=3x-60`
`<=>24x=60`
`<=>x=5/2`
Vậy `S={5/2}`
`b) ``(8x-3)/4-(3x-2)/2=(2x-1)/2+(x+3)/4`
`<=>(8x-3-6x+4)/4=(4x-2+x+3)/4`
`<=>2x+1=5x+1`
`<=>3x=0`
`<=>x=0`
Vậy `S={0}`
`c) ``(x-1)/2-(x+1)/15-(2x-13)/6=0`
`<=>(15x-15-2x-2-10x+65)/(30)=0`
`<=>3x+48=0`
`<=>3x=-48`
`<=>x=-16`
Vậy `S={-16}`
`d)`` (3(3-x))/8+(2(5-x))/3=(1-x)/2-2`
`<=>(9(3-x)+16(5-x))/24=(12(1-x)-48)/24`
`<=>27-9x+80-16x=12-12x-48`
`<=>-9x-16x+12x=12-48-27-80`
`<=>-13x=-143`
`<=>x=11`
Vậy` S={11}`
`e)``(2x-1)/5-(x-2)/3=(x+7)/15`
`<=>(6x-3-5x+10)/15=(x+7)/15`
`<=>x+7=x+7`
`<=>0x=0`
`<=>x in R`
`f)`` (x+3)/2-(x-1)/3=(x+5)/6+1`
`<=>(3x+9-2x+2)/6=(x+5+6)/6`
`<=>x+11=x+11`
`<=>0x=0`
`<=>x in R`
`g)``(2(x+5))/3+(x+12)/2-(5(x-2))/6=x/3+11`
`<=>(4(x+5)+3(x+12)-5(x-2)/6=(2x+66)/6`
`<=>4x+20+3x+36-5x+10=2x+66`
`<=>4x+3x-5x-2x=66-20-36-10`
`<=>0x=0`
`<=> x in R`
`h,``(x-4)/5+(3x-2)/10-x=(2x-5)/3-(7x+2)/6`
`<=>(6(x-4)+3(3x-2)-30x)/30=(10(2x-5)-5(7x+2))/30`
`<=>6x-24+9x-6-30x=20x-50-35x-10`
`<=>6x+9x-30x-20x+35x=-50-10+24+6`
`<=>0x=-30`
`=> x = ∅`
Vậy `S=∅`