Are these Equations correct?

Question

1. 2KClO3 = 2KCl + 3O2

2. 1H2C2O4 + 2NaOH = 1Na2C2O4 + 2H2O

3. 2C10H22 + 31O2 = 20CO2 + 22H2O

4. 4H2 + Fe3O4 = 3Fe + 4H2O

5. 4P + 5O2 = 2P2O5

Answer 1

And how were they solved?

Answer 2

All equation are correct and balanced correctly. I don't understand "how were they solved?"