[tex]a)\\\\3(x^2-2x+3)- \frac{1}{2}(6x^2-4x+10) =3 x^2-6x+9- 3x^2+2x -5=-4x+4\\\\x=-1,5\\\\-4x+4=-4*(-1,5)+4=6+4=10[/tex]
[tex]b)\\\\x(3xy+2y)-y(4x^2+2x-y)= 3x^2y+2xy - 4x^2y-2xy+y^2=-x^2y+y^2\\\\x=-0,2,\ \ y=10\\\\-x^2y+y^2=-(-0,2)^2*10+10^2=-0,04*10+100=-0,4+100=99,6[/tex]
