Trình bày lời giải:
`a)`
`1/3+2/3x=1`
`=>2/3x=1-1/3`
`=>2/3x=3/3-1/3`
`=>2/3x=2/3`
`=>x=2/3:2/3`
`=>x=2/3 . 3/2`
`=>x=1`
Vậy `x=1`
`b)`
`(7/10-x):0,5+3/5=1`
`=>(7/10-x):5/10=1-3/5`
`=>(7/10-x):1/2=5/5-3/5`
`=>(7/10-x):1/2=2/5`
`=>7/10-x=2/5 . 1/2`
`=>7/10-x=2/10`
`=>x=7/10-2/10`
`=>x=5/10`
`=>x=1/2`
Vậy `x=1/2`
`c)`
`|2x-1|=2/3`
`=>[(2x-1=2/3),(2x-1=-2/3):}`
`=>[(2x=2/3+1),(2x=-2/3+1):}`
`=>[(2x=2/3+3/3),(2x=-2/3+3/3):}`
`=>[(2x=5/3),(2x=1/3):}`
`=>[(x=5/3:2),(x=1/3:2):}`
`=>[(x=5/3 . 1/2),(x=1/3 . 1/2):}`
`=>[(x=5/6),(x=1/6):}`
Vậy `x\in{5/6;1/6}`