Answer:
14w
Step-by-step explanation:
Width = w
Length is 6 time its width. so, multiply w by 6
length = 6*w = 6w
Perimeter of rectangle = 2* (length + width)
= 2*(6w + w)
= 2*7w
= 14w
Answer:
26 ft square by 13 ft high
Step-by-step explanation:
The tank will have minimum surface area when opposite sides have the same total area as the square bottom. That is, their height is half their width. This makes the tank half a cube. Said cube would have a volume of ...
2·(8788 ft^3) = (26 ft)^3
The square bottom of the tank is 26 ft square, and its height is 13 ft.
_____
<em>Solution using derivatives</em>
If x is the side length of the square bottom, the height is 8788/x^2 and the area is ...
x^2 + 4x(8788/x^2) = x^2 +35152/x
The derivative of this is zero when area is minimized:
2x -35152/x^2 = 0
x^3 = 17576 = 26^3 . . . . . multiply by x^2/2, add 17576
x = 26
_____
As the attached graph shows, a graphing calculator can also provide the solution.
Answer:

Step-by-step explanation:
Simplify the equation 

Since

and

we have

Car A travels 180miles in 7 hours
Car A travels 25.7 miles an hour because 180/7 = 25.7
Car B travels 350 miles in 4 hours
Car B travels 87.5 miles an hour because 350/4= 87.5
Car C travels 584 miles in 15 hours
Car C travels 38.9 miles an hour because 584/9 = 38.9
Car B has the fastest average speed