`1) x + 1/3 = 3/4`
`x = 3/4 - 1/3`
`x = 9/12 - 4/12`
`x = 5/12`
----------------------------------------
`2) x - 2/5 = 5/7`
`x = 5/7 + 2/5`
`x = 25/35 + 14/35`
`x = 39/35`
-------------------------------------------------
`3) -x - 2/3 = -6/7`
`-x = -6/7 + 2/3`
`-x = -4/21`
⇒ `x = 4/21`
-----------------------------------------------------
`4) 4/7 - x = 1/3`
`x = 4/7 - 1/3`
`x = 12/21 - 7/21`
`x = 5/21`
------------------------------------------------------
`5) x - 1/2 = -2/3`
`x = -2/3 + 1/2`
`x = -4/6 + 3/6`
`x = -1/6`
------------------------------------------------------
`6) 2/7 - x = -3/4`
`x = 2/7 - \frac{-3}{4}`
`x = 8/14 - \frac{-21}{14}`
`x = 29/14`
--------------------------------------------------
`7) -x - ( -7/2) = -3/5`
`-x = -3/5 + (-7/2)`
`-x = -41/10`
⇒ `x = 41/10`
-------------------------------------------------------
`8) 1/3 - (-x) = -2/5`
`1/3 + x = -2/5`
`x = -2/5 - 1/3`
`x = -11/15`
