Hi,
what about this:
Solve[
{323000 == ((250000)^2 + 500000 x y + x (x + 1) y^2)/(250000 + x y),
0.87 == x (y^2)/(323000/1.87)^2}, {x, y}]
The Solutions are
{{x -> 0.230044, y -> -335904.}, {x -> 0.383166, y -> -260272.}}
Cheers,
M.
PS: You will get a warning which you can safely ignore.
