Two straight line: kx+y=1-2k, x-k(y-2)-1. Let P be the point of intersection of these 2 lines. Find the equation of locus of P when the value of k varies.

I found that k = (x-y)/(x+y), x= -(k+1)(2k-1)/(k^2+1), y= (k-1)(2k-1)/(k^2+1).

But I can't find a good method to eliminate the parameter k in above two equations.

Could any one help me?