For balancing equations, only thing you need to see is whether all the elements on the reaction side is equal to the same elements in the product side, in terms of their number of moles.

For example,

a reaction between methane and oxygen forming carbon dioxide and water.

CH₄ + O₂ → CO₂ + H₂O

If you see this reaction is not balanced, because the number of moles for hydrogen and oxygen are not the same on both sides of the equation. So, by hit and trial efforts if you try to put the numbers of moles such that all these elements remains same on both side, you will end up with the following combination,

CH₄ + 2O₂ → CO₂ + 2H₂O.

Similarly, all equations in the world can be balanced.