`5/3 + 1/3 .(x + 1/2) =4`
` 1/3. (x + 1/2) = 4 - 5/3`
` 1/3 . (x + 1/2)= 7/3`
` x + 1/2 = 7/3 : 1/3`
` x + 1/2 = 7`
` x = 7 - 1/2`
` x = 13/2`
Vậy `x = 13/2`
`x+1/10 + x+9/ 2 + x+2/9 = x+8/3 + x+7/4 + x+5/6`
`x+1/10 +1+ x+9/ 2 +1+ x+2/9 +1 = x+8/3+1 + x+7/4+1 + x+5/6+1`
`x+1/10 + 10/10+ x+9/ 2 +2/2 + x+2/9 + 9/9 = x+8/3 + 3/3 + x+7/4 +4/4 + x+5/6 + 6/6`
`x+11/10 + x+11/ 2 + x+11/9 = x+11/3 + x+11/4 + x+11/6`
`x+11/10 + x+11/ 2 + x+11/9 - x+11/3 - x+11/4 - x+11/6 = 0`
`=> (x+11).(1/10+1/2+1/9-1/3-1/4-1/6) =0`
Vì `1/10 + 1/2 + 1/9 - 1/3 - 1/4 - 1/6`$\ne$ `0`
`=> x + 11 = 0`
`=> x = 0 - 11`
`=> x = -11`
Vậy `x = - 11`
