Adesk is on sale for 38% off. the sale price is $527. what is the the regular price

Well the Regular Price is the price before the sale was added. So here's the work that I would put in and in the end, just divide by (1 - 0.38).
Price x (1 - 0.38) = Sale Price (529)
Price x 0.62 = 529
Price = 529 / 0.62 = 853.23

$853.23 was the Regular Price

Expression A:   S= 100+ 100(0.15y)        y=Commission

Expression B:   S= 150+ 150(0.10y)            

Now to get Part B done. Plug in numbers for Y and use the results as the sales continue to increases. For example, start with 5 sales, then go to 10 then 15, and so on and so fourth. Hope I was able help you understand the question a little bit more! :)