x = 20000

y = 15% of z

y + z = x

How do you solve for y and z? What is the formula to the solution?

With x being 20000 I know that roughly y = 2608.7 and z = 17391.3, but that was just from me guessing and then adjusting a few dozen times. I need to know the actual formula to solve for y and z.

And this has a practical purpose if anyone is interested. We own a small business and we have a certain budget for marketing. That budget needs to include commission to the marketing company and what is left will go to the actual ad spend. The commission is 15% of the ad budget. So as our budget goes up or down I need to be able to calculate what the commission and ad spend will be without going over our overall budget. I can continue to guess and adjust but there must be a more practical formula to do that.

Thanks,

-Mort