75x^2+35x-10=0
x1=-0.5; x2=2/3
x1=-2/3; x2=1/5
x^2+6x+3=0
x1= -3/2; x2=4/3
15x^2-6=-13x
6x^2+x-12=0
12x^2+60x+75=0
6x^2-x=2
x1=-6/5; x2=1/3
x1=-5/2
x1=-5.5 x2=-0.55
