Help please

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

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

If (x + 8) is a factor of f(x), which of the following must be true? both x = –8 and x = 8 are roots of f(x). neither x = –8 nor x = 8 is a root of f(x). f(–8) = 0 f(8) = 0