Hello!
When you use sum you add
-2.1x + 3.7 + 5 + 4.9x
Now you add the variables and the constants
-2.1x + 4.9x = 2.8x
3.7 + 5 = 8.7
Combine the two
2.8x + 8.7
The answer is 2.8x + 8.7
Hope this helps!
Answer:
80cause there are 80 sides
One approach is to express
8x2y
so that the numerator and denominator are expressed with the same base. Since 2 and 8 are both powers of 2, substituting 23 for 8 in the numerator of 8x2y gives
(23)x2y
which can be rewritten
23x2y
Since the numerator and denominator of have a common base, this expression can be rewritten as 2(3x−y). In the question, it states that 3x−y=12, so one can substitute 12 for the exponent, 3x−y, which means that
8x2y=212
The final answer is A.
The answer is 9
Step 1- add 4x to both sides and you get 2x+9=27
Step 2-subtract 9 from both sides and you get 2x=18
Step 3-divide by 2x and you get x=9
Answer:
Length = 4cm
Width = 4cm
Height = 8cm
Step-by-step explanation:
The volume of the box = 128cm^3
LWH = Volume
LWH = 128cm^3
The side of the box = $1 per cm^2
The top and bottom of the box = $2 per cm^2
Let C be the cost function
C(LWH) = (1) 2H (L+W) + (2) 2LW
from LWH = 128cm^39
H = 128/LW
put H = 128/LW in equation for C(LWH)
C(LW) = (1) 2(128/LW) + (L+W) +(2) 2LW
= 256/LW(L+W) + 4LW
= 256(1/L + 1/W) + 4LW
Differentiate C with respect to L
dC/dL = 4W - 256/L^2 = 0
Differentiate C with respect to W
dC/dW = 4L - 256/W^2 = 0
The cost is minimum when the two partial derivatives equal 0
From 4W - 256/L^2 = 0
4W = 256/L^2
W = (256/L^2) 1/4
W = 64/L^2
From 4L - 256/W^2 = 0
4L = 256/W^2
L = (256/W^2) 1/4
L = 64/W^2
Since L = W,
L= W = cuberoot (64)
L = W = 4cm
Recall that H= 128/LW
H = 128/(4*4)
H= 128/16
H= 8cm
therefore;
L= 4cm
B= 4cm
H= 8cm
