Answer:
50
Step-by-step explanation:
The distance between the friends is changing at the constant rate of 50 mph.
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The equation for the distance in the westerly direction is ...
w = 30t . . . . . miles, where t is time in hours
The equation for the distance in the southerly direction is ...
s = 40t . . . . . miles, where t is time in hours
Then the total distance between the friends is ...
d = √((30t)² + (40t)²) = √(2500t²) = 50t . . . . miles, where t is time in hours
And the rate of change of distance is the derivative of this with respect to t:
dd/dt = 50 . . . . . . miles per hour
32/36 can be simplified twice into 16/18, and then into 8/9.
Answer:20 + 35 *x=y
Step-by-step explanation:
Answer: Time taken by him in going = 8 hours
Time taken by him in returning = 9 hours
Step-by-step explanation:
Let the total distance from home to New York is x miles,

Also, he drove his car from his home to New York at the rate of 45 mph,
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And, returned over the same road at the rate of 40 mph.
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According to the question,
Time taken by him in returning - Time taken by him in going = 30 minutes = 1/2 hours, ( 1 hours = 60 minutes )
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Hence, the total distance from home to New York = x miles = 360 miles
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