How am i supposed to write this in standard form

Me find the measure to side c and the process to solve the problem you appreciate it : )

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

It says factor each expression 49x-28?