The quadrilateral formed by the pairs of line x y+x+y+1=0, x y+3 x+3 y+9=0 is

Step-by-step solution

Given pair of lines array rlrl x y+x+y+1 & =0 x(y+1)+(y+1) & =0 & & (y+1)(x+1) & =0 & x & =-1 or y=-1 array and second pair of line aligned x y+3 x+3 y+9 & =0 x(y+3)+3(y+3) & =0 (x+3)(y+3) & =0 x=-3 or y & =-3 aligned Quadrilateral so formed by above lines is a square Hence, option (4) is correct.