For this case, the first thing we must do is define variables:
p: plane speed
w: wind speed
With the wind in favor, the speed is:
With the wind against the speed is:
Rewriting both equations, we have the following system of equations:
Then, solving the system of equations (graphically for example), we have the solution is:
Therefore, jet stream's speed:
Answer:
A) p + w = 960; p - w = 600; jet stream's speed = 180 km / h
Answer:
18
Step-by-step explanation:
20/2 + 8
Divide the numerator and denominator by 2
20 / 2
2 / 2
Divide the numbers
10
2 / 2
=
10 / 1
Any expression divided by 1 remains the same
10 + 8 = 18
Answer:
210,000
Step-by-step explanation:
20,000 * 6% = 1,200
20,000 + 1,200 = 21,000
21,000 * 10 = 210,000
Therefore your answer is 210,000
Answer:
$4
Step-by-step explanation:
The two purchases can be written in terms of the cost of an adult ticket (a) and the cost of a student ticket (s):
7a +16s = 120 . . . . . . . . price for the first purchase
13a +9s = 140 . . . . . . . . price for the second purchase
Using Cramer's rule, the value of s can be found as ...
s = (120·13 -140·7)/(16·13 -9·7) = 580/145 = 4
The cost of a student ticket is $4.
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<em>Comment on Cramer's Rule</em>
Cramer's rule is particularly useful for systems that don't have "nice" numbers that would make substitution or elimination easy methods to use. If you locate the numbers in the equation, you can see the X-patterns that are used to compute the numerator and denominator differences.
The value of a is (16·140 -9·120)/(same denominator) = 1160/145 = 8. I wanted to show you these numbers so you could see the numerator X-pattern for the first variable.
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Of course, graphical methods can be quick and easy, too.
