9514 1404 393
Answer:
a) V = 4w²h
b) SA = 4w² +10wh
c) SA = 4w² +37.5/w
d) C = 40w² +225/w
Step-by-step explanation:
The relevant formulas are ...
V = LWH
base area = LW
lateral area = H(2(L+W))
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a) The length is 4 times the width, so the volume is ...
V = (4w)(w)(h)
V = 4w²h
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b) The total surface area is the sum of the base area and the lateral area:
SA = base area + lateral area
SA = (4w)(w) + 2h(4w +w)
SA = 4w² +10wh
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c) The volume is 15 m³, so the height in meters in terms of the width in meters is ...
15 = 4w²h
h = 15/(4w²)
Then the surface area is ...
SA = 4w² +10w(15/(4w²))
SA = 4w² +37.5/w
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d) The equation we have for surface area has one term for base area and a second term for lateral area. We can apply the cost factors to those terms to get the cost of materials:
C = 10(4w²) +6(37.5/w)
C = 40w² +225/w
Answer:
The third score must be larger than or equal to 72, and smaller than or equal 87
Step-by-step explanation:
Let's name "x" the third quiz score for which we need to find the values to get the desired average.
Recalling that average grade for three quizzes is the addition of the values on each, divided by the number of quizzes (3), we have the following expression for the average:

SInce we want this average to be in between 80 and 85, we write the following double inequality using the symbols that include equal sign since we are requested the average to be between 80 and 85 inclusive:

Now we can proceed to solve for the unknown "x" treating each inaquality at a time:

This inequality tells us that the score in the third quiz must be larger than or equal to 72.
Now we study the second inequality to find the other restriction on "x":

This ine
quality tells us that the score in the third test must be smaller than or equal to 87 to reach the goal.
Therefore to obtained the requested condition for the average, the third score must be larger than or equal to 72, and smaller than or equal 87:
Answer:
87.5%
Step-by-step explanation:
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37 hours
You divide 296 by 8 and then you get your answer