We can create two equations here:
(1) Volume = area of square * height of box
85.75 = s^2 h
(2) Cost = 3 * area of square + 1.5 * area of side box
C = 3 s^2 + 1.5 s h
From (1), we get:
h = 85.75 / s^2
Combining this with (2):
C = 3 s^2 + 1.5 s (85.75 / s^2)
C = 3 s^2 + 128.625 s-
Taking the 1st derivative and equating dC/ds =
0:
dC/ds = 6s – 128.625 / s^2 = 0
Multiply all by s^2:
6s^3 – 128.625 = 0
6s^3 = 128.625
s = 2.78 cm
So h is:
h = 85.75 / s^2 = 85.75 / (2.78)^2
h = 11.10 cm
So the dimensions are 2.78 cm x 2.78 cm x 11.10 cm
The total cost now is:
C = 3 (2.78)^2 + 1.5 (2.78) (11.10)
C = $69.47
-5x + y = 5 . . . . . (1)
-4x + 2y = 2 . . . . (2)
(1) x 2 => -10x + 2y = 10 . . . (3)
(2) - (1) => 6x = -10 => x = -8/6 = -4/3
From (1), -5(-4/3) + y = 5 => y = 5 - 20/3 = -5/3
Therefore, x = -4/3; y = -5/3
To solve this, you'll have to divide 13 and 20.
You should get, 0.65. So, the answer is 65%
Answer:
7x-5 in
Step-by-step explanation:
(8x + 2)+(5x+12)+(8x + 2)+?=28x+11
8x+2+5x+12+8x+2+?=28x+11
8x+5x+8x+2+12+2+?=28x+11
13x+8x+16+?=28x+11
21x+16+?=28x+11
21x-21x+16+?=28x-21x+11
16+?=7x+11
16-16+?=7x+11-16
?=7x-5 in