1,2x^2+x=0
6/5x^2+x=0
6x^2+5x=0
x(6x+5)=0
x=0
6x+5=0
x1=0
x2=-5/6
---------------
1,6x+x^2=0
8/5x+x^2=0
8x+5x^2=0
x(8+5x)=0
x=0
8+5x=0
x1=0
x2=-8/5=-1 3/5
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0,5x^2-x=0
x^2-2x=0
x(x-2)=0
x=0
x-2=0
x1=0
x2=2
-----------------
5x^2=x
5x-6=0
x(5x-1)=0
x=0
5x-1=0
x1=0
x2=1/5
----------------
1,6x^2=3x
8/5x^2-3x=0
x(8/5x-3)=0
x=0
8/5x-3=0
x1=0
x2=15/8=1 7/8
---------------------
x=x^2
x-x^2=0
x(1-x)=0
x=0
1-x=0
x1=0
x2=1