Are you trying to solve the equation 'x^2 - 144 = 0'?

If yes, then you need to first click on 'Solve' tab and then type in the equation:

This way you will get the following solution:

Click here to see the solution.

If you want to factor the expression  'x^2 - 144' then you just type ' 'x^2 - 144' without '=0', and you will get the following factorisation:

Click here to see the step by step solving. You can obtain an explanation for any step by clicking on it.