<em>Hi!</em>
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<em>These can be set up as systems of equations.</em>
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<em>Let b = the number of birds, and let d = the number of dogs.</em>
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<em>b + d = 21</em>
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<em>2b + 4d = 76 (this is because birds have 2 legs and dogs have 4 legs.)</em>
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<em>You can solve this using either elimination or substitution.</em>
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<em>Consider marking brainliest.</em>
3⁴-21÷7
According to PEMDAS ( order of operations):
First, Do exponents before multiplying or dividing: 3^4
81-21÷7
Then, divide before subtracting (27÷7 )
81- 3
Finally, subtract
78
I believe the circumference is 52.15.
Answer:
a is the _amplitude_(Length of the blades)_
The vertical shift, k, is the _Mill shaft height_


Step-by-step explanation:
In this problem the amplitude of the sinusoidal function is given by the length of the blades.

The mill is 40 feet above the ground, therefore the function must be displaced 40 units up on the y axis. So:

We know that the blades have an angular velocity w = 3 rotations per minute.
One rotation = 
1 minute = 60 sec.
So:


Finally:
a is the _amplitude_(Length of the blades)_
The vertical shift, k, is the _Mill shaft height_


Answer:
The answer is Phone Surveys.
Step-by-step explanation:
We can say that there are 4 main types of survey methods and they are "In-Person Surveys", "E-mail Surveys", "Phone Surveys" and "Online Surveys".
In-Person Surveys are out of the question in the situation that is described because we need the fastest possible method.
E-mail Surveys and Online Surveys are at completed at a time that the other party chooses so we have no control over how fast we can get the results.
The fastest and best option we can use for the situation Dr. Lee's in is Phone Surveys because they are direct and give quick results over a short amount of time and they can be scheduled according to our needs.
I hope this answer helps.