*Lời giải :
`a) 3 1/2 - 1/2x = 2/3`
`-> 7/2 - 1/2x = 2/3`
`-> 1/2x = 7/2 - 2/3`
`-> 1/2x = 17/6`
`-> x = 17/6 : 1/2`
`-> x = 17/3`
Vậy `x = 17/3`
`b) 1/3 + 2/3 :x = -7`
`-> 2/3 : x = -7 - 1/3`
`-> 2/3 : x = (-22)/3`
`-> x = 2/3 : (-22)/3`
`-> x = (-1)/11`
Vậy `x = (-1)/11`
`c) 1/3x + 2/5 (x - 1) = 0`
`-> 1/3x + 2/5x - 2/5 = 0`
`-> (1/3 + 2/5) . x = 0 + 2/5`
`-> 11/15x = 2/5`
`-> x = 2/5 : 11/15`
`-> x = 6/11`
Vậy `x = 6/11`
`d) (2x - 3) (6 - 2x) = 0`
`->` \(\left[ \begin{array}{l}2x-3=0\\6-2x=0\end{array} \right.\)
`->` \(\left[ \begin{array}{l}2x=3\\2x=6\end{array} \right.\)
`->` \(\left[ \begin{array}{l}x=\dfrac{3}{2}\\x=3\end{array} \right.\)
Vậy `x= 3/2` hoặc `x = 3`
