The first reaction is actually two reactions: $$\ce{4 XeF4 + 8 H2O → 2 Xe + 2 XeO3 + 16 HF + O2}$$ $$\ce{2 XeF4 + 4 H2O → 2 Xe + 8 HF + 2 O2}$$ ---------- $$\ce{6 XeF4 + 12 H2O -> 4 Xe + 2 XeO3 + 24 HF + 3O2}$$