Changes

You can prove that the formula is correct by substituting the formula in place of '''x''' in <math>ax^2+bx+c=0\!</math> and then gradually simplying the rather complicated formula that results, step by step.  Eventually, if all the simplication steps are done correctly, it will simply to 0.

You can prove that the formula is correct by substituting the formula in place of '''x''' in <math>ax^2+bx+c=0\!</math> and then gradually simplying the rather complicated formula that results, step by step.  Eventually, if all the simplication steps are done correctly, it will simply to 0.