`a,3(2x-3)+2(2-x)=-3`
`⇔6x-9+4-2x=-3`
`⇔4x=2`
`⇔x=1/2`
`b,3x(x-2)-x(1+3x)=14`
`⇔3x^2-6x-x-3x^2=14`
`⇔-7x=14`
`⇔x=-2`
`c,2x(x+3)-3(x^2+1)=x+1-x(x-2)`
`⇔2x^2+6x-3x^2-3=x+1-x^2+2x`
`⇔3x=4`
⇔x=4/3`
`d,(x+2)(x-2)-(x-3)(x+5)=0`
`⇔x^2-4-x^2-2x+15=0`
`⇔-2x=-11`
`⇔x=11/2`
`e,(x-3)(x-2)-(x+1)(x-5)=0`
`⇔x^2-5x+6-x^2+4x+5=0`
`⇔-x=-11`
`⇔x=11`
`g,(2x-1)(3-x)+(x-2)(x+3)=(1-x)(x-2)`
`⇔-2x^2+7x-3+x^2+x-6=-x^2+3x-2`
`⇔5x=7`
`⇔x=7/5`
`f,2x(x^2-2)+x^2(1-2x)-x^2=-12`
`⇔2x^3-4x+x^2-2x^3-x^2=-12`
`⇔-4x=-12`
`⇔x=3`
`h,3x(12x-4)-9x(4x-3)=30`
`⇔36x^2-12x-36x^2+27x=30`
`⇔15x=30`
`⇔x=2`
