In order to solve the formula

in terms of d, you simply have to divide both sides by pi:

The total height of the earring is the sum of the diameters of the circles. Given their circumferences, the diameters are

So, the total height is

First, multiply 50*3 to get the answer in feet which is 150 ft.
Then, divide 150 ft by 60 which would be 2.5 ft per second.
The perimeter for the rectangle is 64.5m.
The answer is f(x)=x²+2x when evaluated with -3 gives you the value of 3
It's 78π inches so probably d.