Question

Решите систему уравнений:
1) x^2+y^2=2xy+5x
2) x-y=10

Answer 1

x²+y²=2xy+5x
x=10-y
(10-y)²+y²=2y(10-y)+50-5y
100-20y+y²+y²=20y-2y²+50-5y
100-50-20y+20y+2y²+2y²+5y=0
50+4y²+5y=0
D=√25-4*4*50=<0