Đáp án:
`a)S={-5/6}`
`b)S={-2}`
`c)S={6}`
`d)S={2}`
Giải thích các bước giải:
`a)(3x+2)/2-(3x+1)/6=5/3+2x`
`⇔[3(3x+2)]/6-(3x+1)/6=10/6+(12x)/6`
`⇔3(3x+2)-(3x+1)=10+12x`
`⇔9x+6-3x-1=10+12x`
`⇔9x-3x-12x=10-6+1`
`⇔-6x=5`
`⇔x=-5/6`
Vậy `S={-5/6}`
`b)(4x+3)/5-(6x-2)/7=(5x+4)/3+3`
`⇔[21(4x+3)]/105-[15(6x-2)]/105=[35(5x+4)]/105+315/105`
`⇔21(4x+3)-15(6x-2)=35(5x+4)+315`
`⇔84x+63-90x+30=175x+140+315`
`⇔84x-90x-175x=140+315-63-30`
`⇔-181x=362`
`⇔x=362:(-181)`
`⇔x=-2`
Vậy `S={-2}`
`c)(x+4)/5-x+4=x/3-(x-2)/2`
`⇔[6(x+4)]/30-(30x)/30+120/30=(10x)/30-[15(x-2)]/30`
`⇔6(x+4)-30x+120=10x-15(x-2)`
`⇔6x+24-30x+120=10x-15x+30`
`⇔6x-30x-10x+15x=30-24-120`
`⇔-19x=-144`
`⇔x=(-144):(-19)`
`⇔x=6`
Vậy `S={6}`
`d)(5x+2)/6-(8x-1)/3=(4x+2)/5-5`
`⇔[5(5x+2)]/30-[10(8x-1)]/30=[6(4x+2)]/30-150/30`
`⇔5(5x+2)-10(8x-1)=6(4x+2)-150`
`⇔25x+10-80x+10=24x+12-150`
`⇔25x-80x-24x=12-150-10-10`
`⇔-79x=-158`
`⇔x=(-158):(-79)`
`⇔x=2`
Vậy `S={2}`
