X^2 + y^2 + 2(x+y) + 2 = 0

Vẫn bài 1
g) x^2+y^2+2(x+y)+2=0
h) 4x+y^2-4x-4y+6=0
i) x^2-7x+12=0
k) 1/2 × x+7/8x=11