A student makes and sells necklaces at the beach during the summer months. The material for each necklace costs her $6 and she has been selling about 30 per day at $10 each. She has been wondering whether or not to raise the price, so she takes a survey and finds that for every dollar increase she would lose 4 sales a day,
(a) If she increases her pr by x dollars, then her price will be 10+x
produce the necklaces for a day will be 6(30-4x)
✓ dollars.
dollars, her number of sales for the day will be 30-(4x)
necklaces, and her cost to
(b) Write her profit P as a function of the number x of dollar increases in price: