A quantity with an initial value of 400 grows exponentially at a rate such that the quantity doubles every 8 days. What is the value of the quantity after 29 days, to the nearest hundredth?​

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm