<span>The rectangle with the largest area with a given perimeter will be a square - so the sides will be equal. So we need to find length of side, L, such that 4*L=168.
L = 168/4
L=42.
So the dimensions of the rectangle that maximizes the area with a perimiter of 168 feet are: 42 feet by 24 feet.</span>
400 is another way to right 4 hundreds
<span>average rate of change = (f(7) - f(5)) / (x7 - x5)
</span>f(7) = <span>12 (7^3) + 12 = 4128
f(5) = </span>12 (5^3) + 12 = 1512
so
average rate of change = (4128 - 1512)/(7-5)
average rate of change = 2616 / 2
average rate of change = 1308
hope it helps