The equilibrium constant Kc is 54.3 at 430°C for the following reaction:
H₂(g) + I₂(g) ⇌ 2HI(g)

Initially, 0.90 M H₂, I₂, and HI are introduced into a 5.0-L flask and allowed to come to equilibrium. What are the equilibrium concentrations of H₂, I₂, and HI in the flask?