Simplify the following expressions.
1 answer:
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Answer:
.
Step-by-step explanation:
Let represent the mass (in pounds) of that
copper alloy required, such that the final mixture would contain
copper by mass.
Consider: if pounds of that
copper alloy is mixed with
pounds that
copper alloy, what would be the mass of copper in the mixture?
- Mass of copper in
pounds of that
copper alloy:
.
- Mass of copper in
pounds of that
copper alloy:
.
Therefore, the mixture would contain of copper.
The mass of that mixture would be . The mass fraction of copper in that mixture would be:
.
This ratio is supposed to be equal to . These two pieces of equations combine to give an equation about
:
.
.
Simplify and solve for :
.
.
.
Therefore, of that
alloy would be required.
Here’s the answer for the first question and the second one stays 10k
Using the relation between velocity, distance and time, it is found that the rate of the current is of 3.33 mph.
<h3>What is the relation between velocity, distance and time?</h3>Velocity is distance divided by time, hence:
v = d/t
A small motorboat travels 12mph in still water. With the current, upstream, 46 miles are traveled in t hours, hence:
12 + r = 46/t
r = 46/t - 12
Downstream, the time is of t + 2 hours, hence:
12 - r = 46/(t + 2)
r = 12 - 46/(t + 2)
Hence, equaling the values for r:
46/t - 12 = 12 - 46/(t + 2)
46/t + 46/(t + 2) = 24
92t + 92 = 24t² + 48t
24t² - 44t - 92 = 0
Using a quadratic equation calculator, the solution is t = 3. Hence the rate is found as follows:
r = 46/t - 12 = 46/3 - 12 = 3.33 mph.
More can be learned about the relation between velocity, distance and time at brainly.com/question/28155966
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