If x+y>0 when x>y, which of the following cannot be true?
Find the equation of the circle which circumscribes the triangle formed by the lines: (i) x+y+3=0,x−y+1=0 and x=3 (ii) 2x+y−3=0,x+y−1=0 and 3x+2y−5=0 (iii) x+y=2,3x−4y=6 and x−y=0. (iv) y=x+2,3y=4x and 2y=3x.