A manufacturer wants to construct a box whose base length is 4 times the base width. The material to build the top and bottom cost 8 dollars per ft.2 and sides 5 dollars per ft.2. If the box must have a volume of 72 ft.3, determine the dimensions that will minimize cost.

width = 1.77845 ft

length = 7.1138 ft

height = 5.691 ft

total cost = $759.09

Step-by-step explanation:

volume = length x width x height

length = 4 width

base of the rectangle = 4 x 1 w = 4w²

72 (volume) = 4w²h

18 = w²h

f(c) = (2 x 4w² x $10) + (2 x wh x $5) + (2 x 4wh x $5)

f(c) = 80w² + 10wh + 40wh

f(c) = 80w² + 50wh

since we need only 1 variable (width), we have to substitute h:

h = 18/w²

f(c) = 80w² + 50w(18/w²) = 80w² + 900/w

f'(c) = 160w + 900/w²

0 = (160w³ + 900)/w²

0 = 160w³ + 900

0 = 20(8w³ + 45)

0 = 8w³ + 45

8w³ = -45

w³ = -45/8

w = ∛-45/8 = -1.77845 and 1.77845

since w cannot be negative, then it must be 1.77845

total amount of money that he should pay if he has not used his duty free exemption is $98

step-by-step explanation:

given a united states citizen returning to the states declares the following items at the customs office: 3 shirts at $8.50 each 2 dresses at $27.50 each 1 pair of gold cuff links at $17.50 per pair. we have to find how much he pay

cost of 3 shirts if one cost at $8.50 is

cost of 2 dresses if one cost at $27.50 is  

cost of 1 pair of gold cuff at $17.50

so, total amount of money that he should pay if he has not used his duty free exemption is   $25.5+$55+$17.50=$98

i believe the correct answer is option 4.principalities were small territories that were run by russian rulers.

which statement correctly defines principalities in northern asia in the 1200s? principalities were small territories that were run by russian rulers.

hope i could ! : )