`***`Lời giải`***`
a)
`(2.(3x+1)+1)/4 - 5 = (2.(3x-1))/5-(3x+2)/10`
`<=>(5[2.(3x+1)+1])/20 - 100/20 = (8(3x-1))/20-(2(3x+2))/20`
`<=>5[2.(3x+1)+1] - 100= 8(3x-1)-2(3x+2)`
`<=>5(6x+2+1) - 100= 24x-8-6x-4`
`<=>5(6x+3) - 100= 24x-8-6x-4`
`<=>30x+15 - 100= 24x-8-6x-4`
`<=>30x-24x+6x =100 -15-8-4`
`<=>12x =73`
`<=>x=73/12`
Vậy `S={73/12}`
b)
` (x+1)/11-(2x-5)/15=(3x-47)/17-(4x-59)/19`
` <=>x/11+1/11-(2x)/15+5/15=(3x)/17-47/17-(4x)/19+59/19`
` <=>x/11-(3x)/17-(2x)/15+(4x)/19=-5/15-1/11-47/17+59/19`
` <=>x/11-(2x)/15-(3x)/17+(4x)/19=-14/33+110/323`
` <=>(-7x)/165+(11x)/323=-14/33+110/323`
` <=>x=10`
Vậy `S={10}`