A classmate asks for your help writing an equilibrium

Question

1) Describe the different ways to shift the equilibrium to the left for the following reaction:

2 A (s) + 2 BC (aq) --> 2 AB (aq) + C₂(g).

Justify your answer.

ΔH = -352 kJ 

2) A classmate asks for your help writing an equilibrium expression for the combustion of methane gas: CH_4(g) + 2 O_{2(g)  -->} CO_2(g) + 2 H₂O_(l). Explain to her why it is not meaningful to create an equilibrium expression or calculate an equilibrium constant for this reaction.