We are given with a cubic equation which represents 3-lines. Let lines have, y−m1x=0;y−m2x=0 and y−m3x=0 Then, (y−m1x)(y−m2x)(y−m3x)=0 is the combined equations Which in this case is, Which in this case is, y3−6xy2+11x2y−6x3=0 By comparison we are able to put above equation are, (y−x)(y−2x)(y−3x)=0 So, lines are, L1⇒y−x=0 L2⇒y−2x=0 and L3⇒y=3x=0 Their intersection points with x+y=1 are, P≡x+y=1 and y−x=0 ⇒P≡(