To get the net chemical equation, you should write out the
two equations and then add the elements or compounds on each side. And then cancel
ones that are on each side.
But first, you'll need to multiply the first equation by 6.
6CaC2(s) + 12H2O(g) + 6C2H2(g) + 3CO2(g) + 4H2O(g) = 6C2H2(g) + 6CaOH2(s) +
5CH2CHCO2H(g)
6CaC2(s) + 12H2O(g) + 3CO2(g) + 4H2O(g) = 6CaOH2(s) + 5CH2CHCO2H(g)
6CaC2(s) + 16H2O(g) + 3CO2(g) = 6CaOH2(s) + 5CH2CHCO2H(g) is the net chemical equation.