You have typed in the following equation:

6 = 10B+12C

The equation has two variables: 'B' and 'C'.

The solution that you see in the solver is for 'B':

You can obtain an explanation for any step by clicking on it. Please note that you cannot click on the very first expression, which is the original problem. Quite often, several transformations will be performed within the same step. Use the explanation navigation buttons to step through all of them: