Уравнения 1) 11x^2-6x-27=8x^2-6x 2)26+5y-0.5y^2=2.5y^2+26 3) -7x^2+13x+9= -19+13x 4)21z+11=11+17z-5z^2

1)11x^2-6x-27-8x^2+6x=3x^2-27
2)26+5y-0,5y^2-2,5y^2-26=-3y^2+5y
3)-7x^2+13x+9+19-13x=-7x^2+28
4)21z+11-11-17z+5z^2=5z^2+4z

1)11x^2-6x-27=8x^2-6x
3x^2=27
x^2=9
x=+-3
2)26+5y-0.5y^2=2.5y^2+26
-3y^2+5y=0
3y^2-5y=0
y(3y-5)=0
y=0 или y=5/3
3)-7x^2+13x+9= -19+13x
-7x^2=-28
x^2=4
x=+-2
4)21z+11=11+17z-5z^2
5z^2+4z=0
z(5z+4)=0
z=0 или z=-4/5