The selling price of an item is $360. It is marked down by 10%, but this sale price is still marked upfrom the cost of $270. Find the markup from cost to sale price.

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?