what does "etc" mean? you should not leave out any part of a question if you need someone to help you. you may leave out something important.

a system of equations is not needed here.

Let the amount gained in sales be

Then working at Radio Barn one can earn dollars.

Working at Woofer one can earn

To find the amount of sales we have to make to get equal salaries, just equate the two, thus we need to solve:

for