Question

x^2-xy+y^2=21 y^2-2xy+15=0 помогите решить систему

Answer 1

$x^2+y^2-xy=21\\ y^2-2xy+15=0\\ x^2+xy=36\\ y=frac{36-x^2}{x}\\ frac{(36-x^2)^2}{x^2}-2(36-x^2)+15=0\\ (36-x^2)^2-2x^2(36-x^2)+15x^2=0\\ 3(x-4)(x+4)(x^2-27)=0\\ x=+-4\\ x=+-3sqrt{3}\\ y=+-5\ y=+-sqrt{3}$