Answer:
Well then...
Step-by-step explanation:
to balance the equation
H2 + O2 -> H2O
we see there is too little oxygens on the right side
so put 2 after H20
H2 + O2 -> 2H2O
now the oxygens are balanced but there are too little hydrogens on the left side so put
a 2
2H2 + O2 -> 2H2O
This is now balanced!