Everything in #11 question is already balanced, just put a one in front of the elements.
For question 12 you have to put a 3 in front of the first Fe to balance out the number of Fe’s in the equation, then to balance out oxygen, you have to put a 4 in front of H2O which gives you 4 oxygen but 8 hydrogen. To fix this you put a 4 in front of the 2 hydrogen atoms at the end of the equation to get 8 hydrogen atoms.
