a) `x : 3/2 = -12/5`
`⇔ x=-12/5 xx 3/2`
`⇔x = -36/10`
`⇔x=-18/5`
`b)-5/2 x + 7/3 = 5/6`
`⇔-5/2 x = 5/6 - 7/3`
`⇔-5/2 x = -3/2`
`⇔x = -3/2 : -5/2`
`⇔x = 3/5`
`c)3/2+2/5 - (2x-3)=4 1/5`
`⇔ 3/2 + 2/5 - 2x + 3 = 21/5`
`⇔-2x = 21/5 - 3/2 - 2/5 - 3`
`⇔-2x = -7/10`
`⇔x= -7/10 : (-2)`
`⇔x = 7/20`
`d)(3/4 - x)^2 - 2,5 = 9/16`
`⇔(0,75 - x)^2 = 0,5625 + 2,5`
`⇔(0,75 - x)^2 = 3,0625`
`⇔(0,75 - x)^2 = (√3,0625)^2`
⇔\(\left[ \begin{array}{l}0,75 - x =1,75\\0,75 - x=-1,75\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-1\\x=2,5\end{array} \right.\)