Given, the equation of two planes ax + by + cz + d = 0 and ax + by + cz + d1 = 0, where d=d1 Taking the ratio of direction ratios of the plane, we have ⇒aa=bb=cc⇒1=1=1 The ratio of direction ratios of the plane ⇒ax+by+cz+d=0 and ax+by+cz+d1=0 is same ⇒ The plane ax+by+cz+d=0 and ax+by+cz+d1=0 are parallel. Hence, The two planes ax+by+cz+d=0 and ax+by+cz+d1=0, where d=d1, have no points in common.