Question

решите уравнение 5x^2+y^2-4xy-4x+4=0

Answer 1

 $5x^2+y^2-4xy-4x+4=0 \\ 4x^2+y^2-4xy+x^2-4x+4=0\\ (2x-y)^2+ (x-2)^2=0\\ 2x-y=0 \\ x-2=0\\\\ x=2\\ y=4$