Balance the following equation.  ___C3H8  + ___ O2  ==>___ CO2  + ___   H2O

Sure, here are the steps to balance the chemical equation:

1. Write down the unbalanced equation: C3H8 + O2 --> CO2 + H2O

2. Balance the equation one element at a time. Start with the carbon (C) atoms. There are 3 carbon atoms on the left side (in C3H8), so you need 3 carbon atoms on the right side (in CO2). To do this, put a 3 in front of CO2: C3H8 + O2 --> 3CO2 + H2O

3. Next, balance the hydrogen (H) atoms. There are 8 hydrogen atoms on the left side (in C3H8), so you need 8 hydrogen atoms on the right side (in H2O). To do this, put a 4 in front of H2O: C3H8 + O2 --> 3CO2 + 4H2O

4. Finally, balance the oxygen (O) atoms. There are 10 oxygen atoms on the right side (6 in 3CO2 and 4 in 4H2O), so you need 10 oxygen atoms on the left side (in O2). To do this, put a 5 in front of O2: C3H8 + 5O2 --> 3CO2 + 4H2O

So, the balanced equation is: C3H8 + 5O2 --> 3CO2 + 4H2O