What is the correct balanced equation for the following equilibrium constant expression?

Question

anonymous · Answer

$$\frac{ [CO]^2x[O2] }{ CO2 }^2$$

anonymous · Answer

Answers
CO2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. CO (g) + ½ O2 (g)
 CO2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. CO (g) + O2 (g)
 2 CO2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. 2 CO (g) + O2 (g)
 2CO (g) + O2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. CO2 (g)