Straight line

Submitted by alpha on Sat, 11/21/2009 - 04:22.

If the equations (q-r)x+(r-p)y+(p-q)=0
and $(q^3-r^3)x+(r^3-p^3)y+(p^3-q^3)=0$ represent the same line , then prove that either p=q or q=r or p+q+r=0