equilibrium constants for the following reactions

4Cu(s) + O2(g) 2Cu2O(s), K1
2CuO(s) Cu2O(s) + 1/2O2(g), K2
what is K for the system
2Cu(s) + O2(g) 2CuO(s)
?

1 answer

(K1 ^(1/2)) / (K2)

K1,to the power of 1/2, over K2