1/x^2-4xy-4y^2+2/4y^2-x^2+1/4y^2+4xy+x^2

ответ. 1. x^2+4*x*y=21; 3*x-y=8; y=3*x-8; x^2+4*x*(3*x-8)=21; 13*x^2-32*x-21=0; x1=3; x2=-7/13;
2. x^2+y^2=52; x*y=24; (x+y)^2=100; 1). x+y=10; 2). x+y=-10;
1). y=10-x; x*(10-x)=24; x^2-10*x-24=0; x1=-2; x2=12; y1=12; y2=-2;
2). y=x+10; x*(10+x)=24; x^2+10*x-24=0; x3=2; x4=-12; y3=12; y4=-2;