How to link two-way data entered into inputs, so that when you enter values ​​in one, the result appears in the other?

Question

Angular

Hello dear visitors. As a newbie to angularJS, I have the following question. How to link two-way data entered into inputs, so that when you enter values ​​in one, the result appears in the other? The result should be the following:
There is a monthly payment (a known value), two inputs, the discount percentage is entered in one, the discount amount is entered in the other. I need that when entering percentage values, in the second input, by mathematical calculations, the amount of this very discount appears. And vice versa, so that when entering the discount amount, the percentage of the discount appears in the first input as well as a result of the mat. actions. Something like this https://plnkr.co/edit/eScyfsT7i6Tl4wQdee6v?p=preview only in working form)

Answer 1

something like this https://plnkr.co/edit/1mcttiOdxbjyMDlKstmi?p=preview