2-methyl propanol is also known as "Isobutane". Combustion is simply reaction with molecular oxygen as a fuel:
The formulation is
Combustion is just a complete reaction with oxygen fuel (e.g.
For a start, isobutanol contains 10 hydrogen atoms, which means that each mole yields 5 moles of water (because each water molecule contains 2 hydrogen atoms).
Then isobutanol contains 4 carbon atoms, so each mole yields 4 moles of carbon dioxide.
So if you add the relevant numbers of moles to the water and carbon dioxide, you will find that you then have a total of 13 oxygens on the "Products" side of the equation (8 in carbon dioxide and 5 in water), but only 3 on the "Reactants" side.
To balance out everything add a "6" to the oxygen giving you a total of 13 oxygens on each side.