Problem 1
<h3>Answers: n = 3 or n = 5</h3>
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Work Shown:

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Problem 2
<h3>Answers: c = 1 or c = -2/3</h3>
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Work Shown:

81 miles
M=81
You need to multiple .90 by 81 Mille and the result you add the 55 and you got 127.9 that is more that the actual 127
The correct answer is B) 28.2 m
Cosx= sin(90-x)
From the RHS,
sin(90-x)= sin90cosx-cos90sinx
Since sin90=1, cos90=0
sin90cosx-cos90sinx=cosx-0=cosx (proven)