What is (b-8)x4? math homework:)

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

Will mark the brainliest.paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?

Ellie spent $88.79 at the computer stote. she had $44.50 left to buy a cool hat. how much money did she originally have? write and solve an equation to answer the question.