The perimeter of a rectangle is 78 units. the length is 5 units more than 3 times the width. find the length and width of the rectangle.

W = 8.5 units; L = 30.5 units

Step-by-step explanation:

The formula for the perimeter of a rectangle is P = 2L and 2W, where L and W represent the length and the width respectively.  Here, L = 3W + 5.  Adapting the formula P = 2L and 2W, we get:

78 = 2L + 2W  =  2(3W + 5) + 2W, or

6W + 10 + 2W = 78, or

8W = 68, or W = 68/8 = 8.5 units

If W = 8.5 units, then L = 3(8.5 units) + 5 units = 30.5 units

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)