a rock is thrown from the top of a tall building. the distance in feet between the rock and the ground t seconds after it is thrown is given by d=-16t^2- 4t + 522. how long after the rock is thrown is it 390 feet from the ground?

A metal cube dissolves in acid such that an edge of the cube decreases by 0.43 mm per minute. How fast is the volume of the cube changing when the edge is 8.9 mm?

Suppose that the area of the x+2 by x+4 rectangle drawn in the last exercise is actually 120. Does your rectangle have an area of 120? If not, then draw an x+2 by x+4 rectangle with an area of 120. What is x? Is x an integer?

a window is shaped like a rectangle whose perimeter is 306 in. the length is 8 times as long as the width. find the length and the width

5) You plan to build a playing field in the shape of a rectangle with a semicircular region at each end, so that races can be held around the perimeter of the field. If you want the total perimeter of the field to be 1000 m, what dimensions should your field have to maximize the area of the...

Identify the equation of variation for the given situatuions: y varies directly as x, and y=6 when x=9

A particular company produces widgets. Each widget sells for $9, and the variable cost of producing each unit is 40% of the selling price. If the monthly fixed costs incurred by the company are $50,000, what is the break-even point?

ap

X minus 1518 divided by 325

A car rental agency rents 190 cars per day at a rate of 31 dollars per day. For each 1 dollar increase in the daily rate, 5 fewer cars are rented. At what rate should the cars be rented to produce the maximum income, and what is the maximum income?