Решите уравнения: 1) (х-3)²+(х+4)²-(х-5)²=17х+24; 2) (х+5)²+(х-2)²+(х-7)(х+7)=11х+80.

Question

Решите уравнения:

1) (х-3)²+(х+4)²-(х-5)²=17х+24;
2) (х+5)²+(х-2)²+(х-7)(х+7)=11х+80.

Answer 1

1) x^2-6x+9+x^2+8x+16-x^2+10x-25=17x+24;
x^2+2x+25-25+10x=17x+24;
x^2+12x=17x+24;
x^2-5x-24=0;
D=121; x1=8; x2=-3;
2) x^2+10x+25+x^2-4x+4+x^2-49=11x+80;
3x^2+6x-20=11x+80;
3x^2-5x-100=0;
D=1225; x1=5+35/6=40/6=20/3;
x2=-30/6=-5;

Answer 2

1) (х-3)^2+(х+4)^2-(х-5)^2=17х+24
х^2-6х+9+х^2+8х+16-х^2+20х-25=17х+24
х^2-5х-36=0
D=25-4*36=169
x1=13+5/2=8
x2=13-5/2=4
2)(x+5)^2+(x-2)^2+(x-7)(x+7)=11x+80
x^2+10x+25+x^2-4x+4+x^2-49=11x+80
3x^2-5x-100=0
D=25+1200=1225
x1=35+5/6=20/3
x2=35-5/6=5

Comments

Почему у тебя 20х-25=17х+24???