A plane with the equation (a,b,c > 0) together with the positive coordinate planes forms a tetrahedron of volume . Find the plane that minimizes V if the plane is constrained to pass through the point P = (1,1,1).

I'm not sure how to this, trying for and I got a=b=c. Which I don't think is right after using Lagrange multipliers. help!

= [(1/6)bc, (1/6)ac,(1/6)ab] and I set it to equal each other :/ help?