\frac{1}{2}x(4-6x)-\frac{1}{3}x(9x-12)=-2x(3x+1)
\frac{1*4*x}{2}-\frac{1*6*x^2}{2}-(\frac{1*9*x^2}{3}-\frac{1*12*x}{3})=-6x^2-2x
2x-3x^2-3x^2+4x=-6x^2-2x
6x-6x^2+6x^2+2x=0
8x=0
x=0
…
(x+2)^2=x^2
x^2+4x+4=x^2
x^2+4x-x^2=-4
4x=-4
x=-1
…
(x+2)^2=x^2-2
x^2+4x+4-x^2=-2
4x=-2-4
4x=-6
x=-1,5
…
y(2y-1)=2(2+y)^2
2y^2-2y=2(4+4y+y^2)
2y^2-2y=8+8y+2y^2
2y^2-2y-8y-2y^2=8
-10y=8
x=-0,8
…
(\frac{1}{2}x-4)^2=(\frac{1}{2}x+4)^2
(\frac{1}{2}x)^2-2*\frac{1}{2}x*4+4^2=(\frac{1}{2}x)^2+2*\frac{1}{2}x*4+4^2
\frac{1}{4}x^2-4x+16=\frac{1}{4}x^2+4x+16
\frac{1}{4}x^2-4x-\frac{1}{4}x^2-4x=16-16
-8x=0
x=0