`a) 1/3 x + 1/2 = 7/3`

`1/3 x = 7/3 − 1/2`

`1/3 x = 11/6 `

`x = 11/6 : 1/3`

`x = 11/2`

Vậy `x = 11/2`

`b) 9/4 − 5/4 (x + 2/3) = 1 `

`9 − 5(x + 2/3) = 4`

`9 − 5x − 10/3 = 4`

`27/3 − 10/3 − 5x = 12/3`

`17/3 − 5x = 12/3 `

`−5x = −5/3 `

`x = 1/3 `

Vậy `x = 1/3`

`c) (x − 3/2)² : 10/3 + 3/5 = 1,8 `

`(x − 3/2)² × 3/10 + 3/5 = 9/5`

`(x − 3/2)² × 3/10 = 6/5 `

`(x − 3/2)² = 4 `

`TH1: x − 3/2 = 2` hoặc `TH2: x − 3/2 = −2`

`x = 2 + 3/2` hoặc `x = -2 + 3/2`

`x = 7/2` hoặc `x = −1/2`

Vậy `x ∈ {7/2; -1/2}`