. Consider the following equilibrium: N2O4(g) ⇌ 2 NO2(g) Kc= 4.61 x 10-3 at 25oC The N2O4 – NO2 equilibrium mixture in the flask on the left is allowed to expand into the evacuates flask on the right.. 0.971 mol N2O4 2.25 L and 25C 0.0580 mol NO2 0.750 L 25oC What is the composition of the gaseous mixture when equilibrium is reestablished in the system consisting of the two flasks? (Ans. 0.943 mol N2O4, 0.114 mol NO2) The solution gets it as (.00193+2x)^2/(.324-x) = 4.61x10^-3 They canceled out the x on the bottom and not the top

Question

. Consider the following equilibrium: N2O4(g) ⇌ 2 NO2(g)   Kc= 4.61 x 10-3 at 25oC 
The N2O4 – NO2 equilibrium mixture in the flask on the left is allowed to expand into the evacuates flask on the right..
0.971 mol N2O4 <change to>  2.25 L and 25C
0.0580 mol NO2
0.750 L
25oC
What is the composition of the gaseous mixture when equilibrium is reestablished in 
the system consisting of the two flasks? (Ans. 0.943 mol N2O4, 0.114 mol NO2)

The solution gets it as 
(.00193+2x)^2/(.324-x) = 4.61x10^-3

They canceled out the x on the bottom and not the top