Show that `2x+3y+7=0` represents a plane perpendicular to xy-plane.

Show that the equations ax+by+r=0, by+cz+p=0, cz+ax+q=0 represents the planes perpendicular to xy, yz, zx-planes respectively.

Show that the equations ax+by+r=0 by + cz + p =0, cz+ax+q=0 represents the planes perpendicular to xy, yz, zx - planes respectively.

In the space the equation by + cz + d = 0 represents a plane perpendicular to the ..... plane

Prove that the equation 2x^(2)+3xy-2y^(2)-x+3y-1=0 represents a pair of perpendicular straight lines.

Show that the equation x^(2)-y^(2)-x+3y-2=0 represents a pair of perpendicular lines and find their equations.