Question

решить уравнение : x^2-2x+y^2-4y+5=0

Answer 1

$x^2-2x+1+y^2-4y+4=0\ (x-1)^2+(y-2)^2=0\ left { {{(x-1)^2=0} atop {(y-2)^2=0}} right.\ x=1\ y=2$