If You multiply each number of your dial pad, what will be the result?

Pick a number.  Double it. Multiply the result by 3.  Add 24. Divide by 6. Subtract your original number.  Is the result always the same? Write a convincing argument for your answer.

Hi my questions is

what two numbers added together equal 1. When you multiply the two numbers together you get -30 what are the two numbers