Пошаговое объяснение:
y=x^2-5x+2;
x^2-5x-1=y-3
(x^2-5x+2)(x^2-5x-1)=28. =>y(y-3)=28 => y^2-3y-28=0 D=9+4*28=121 ;y=(3+11)/2=7 y=(3-11)/2=-4
1) x^2-5x+2=7;
2) x^2-5x+2=-4;
x^2-5x-5=0; D=25+20=45
x1=(5+3√5)/2; x2=(5-3√5)/2;
x^2-5x+6=0; D=25-4*6=25-24=1;
x3=(5+1)/2=3; x4=(5-1)/2=2;
x1=(5+3√5)/2;
x2=(5-3√5)/2;
x3=(5+1)/2=3;
x4=(5-1)/2=2;
x1*x2*x3*x4=((5+3√5)/2)((5-3√5)/2)*3*2=-5*6=-30
Пошаговое объяснение:
y=x^2-5x+2;
x^2-5x-1=y-3
(x^2-5x+2)(x^2-5x-1)=28. =>y(y-3)=28 => y^2-3y-28=0 D=9+4*28=121 ;y=(3+11)/2=7 y=(3-11)/2=-4
1) x^2-5x+2=7;
2) x^2-5x+2=-4;
1) x^2-5x+2=7;
x^2-5x-5=0; D=25+20=45
x1=(5+3√5)/2; x2=(5-3√5)/2;
2) x^2-5x+2=-4;
x^2-5x+6=0; D=25-4*6=25-24=1;
x3=(5+1)/2=3; x4=(5-1)/2=2;
x1=(5+3√5)/2;
x2=(5-3√5)/2;
x3=(5+1)/2=3;
x4=(5-1)/2=2;
x1*x2*x3*x4=((5+3√5)/2)((5-3√5)/2)*3*2=-5*6=-30