Teresa bought 4 CDs that were each the same price. Including sales tax, she paid a total of 53.60 . Each CD had a tax of 0.80 . What was the price of each CD before tax?

Which statement is true about the local minimum of the graphed function? over the interval[-4,-2], the local minimum is 0. over the interval [-2,-1] , the local minimum is 25. over the interval [-1,4], the local minimum is 0. over the interval [4,7], the local minimum is -7