`x : 3/4 = ( 2/3 + 1/3 ) : 3/4`
`x : 3/4 = 1 : 3/4`
`x : 3/4 = 1 xx 4/3`
`x : 3/4 = 4/3`
`x = 4/3 xx 3/4`
`x = 12/12 = 1`
`x:3/4=(2/3+1/3):3/4`
`x:3/4=3/3:3/4`
`x:3/4=4/3`
`x=4/3xx3/4`
`x=1`
`x:3/4=(2/3+1/3):3/4`
`x:3/4=3/3:3/4`
`x:3/4=1:3/4`
`x:3/4 = 4/3`
`x=4/3 xx 3/4`
`x=1`
Vậy `x=1`
`x:3/4=(2/3 + 1/3):3/4`
`=>x:3/4= 3/3 : 3/4`
`=>x:3/4=1 : 3/4`
`=>x:3/4=1 xx 4/3`
`=>x:3/4=4/3`
`=>x= 4/3 xx 3/4`
`=>x= 1`