Question

найдите корни уравнения: 1)26+5y-0.5y^2=2.5y^2+26
2)-7x^2+13x+9=-19+13x

Answer 1

1) 26+5y-0.5y^2=2.5y^2+26
26+5y-0.5y^2-2.5y^2-26=0
5y-3y^2=0
y(5-3y)=0
y1=0 y2=1.66
2)-7x^2+13x+9=-19+13x
-7x^2+13x+9+19-13x=0
-7x^2+28=0
7x^2=28
x^2=3
x1=√3
x2=-√3