Two lines from the family of lines (1+2λ)x−(1+λ)y+1=0 and the line x+y=5 form an equilateral triangle. the equation of the two lines can be

Let BC be x+y=5, then P be the point of concurency of family of lines  ∴ P= (1,2) let A be midpoint of BCequation of PA is x-y+1=0 ; PB and PCmake equal angles π6 with  x-y+1=0