Find the slope (-6,2) (4,5)
1 answer:
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Answer:
see the explanation
Step-by-step explanation:
<em><u>The question is </u></em>
Identify the domain and the range, using words and inequalities
Let
x -----> the number of kilowatt-hours (kWh) of electricity per month
y ----> the price per month
we know that
Part 1) For the value of x between 0 kWh and 400 kWh
The price is equal to
therefore
The domain is the interval ------> [0,400)
The domain is all real numbers greater than or equal to 0 kWh and less than 400 kWh
The range is ($30)
The range is equal to $30
Part 2) For the value of x equal to 400 kWh or more per month
The domain is the interval -----> [400, infinite)
The domain is all real numbers greater than or equal to 400 kWh
The price is
<em>Find the range</em>
For x=400 kWh
so
The range is the interval -----> [38.8, infinite)
Answer:
<em>Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour</em>
Step-by-step explanation:
<u>Relative Speed</u>
When a body is moving at a constant speed v, the distance traveled in a time t is:
When Roberto rows downstream, his speed in still water is added to the speed of the water, making it easier to travel the required distance.
When Roberto rows upstream, his speed in still water is affected by the speed of the water, both are subtracted and the required distance is covered in more time.
Let's call
x = Roberto's rowing speed in still water
y = Speed of the river current
The speed when rowing downstream is x+y, thus the distance traveled is
Where t1=2.5 hours. Substituting values:
Rearranging, we find the downstream equation:
The speed when rowing upstream is x-y, and the distance traveled is
Where t2=5 hours. Substituting values:
Rearranging, we find the upstream equation:
Multiplying [1] by 2:
Adding this equation to [2]:
Solving:
Dividing [2] by 5:
Solving for y
Thus, Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour