The number of ordered pairs (x,y) where x,yϵ R satisfying x2+y2−xy=4(x+y−4) is
Open in App
Solution
x2+y2−xy=4(x+y−4) 2x2+2y2−2xy=8(x+y−4) (x2−2xy+y2)+(x2−8x+16)+(y2−8y+16)=0 (x−y)2+(x−4)2+(y−4)2=0 ⇒x−y=0,x−4=0,y−4=0 Hence there is only one solution (4,4)