You can multiply the digits or the place value. Either way, you will get the same result.
(2 thousands, 7 tens) × 10 =
... (20 thousands, 70 tens)
or
... (2 ten-thousands, 7 hundreds)
Answer:
a) T(r) = r.D(r)
b) 975 people per square mile.
Step-by-step explanation:
(a)
The units of D(r) are

when multiplying the density by the area we get the amount of people in that area, so

(b)
The average rate of change of T(r) over the interval [5,7] is

but D(7) = 350 and D(5) = 100, so

and the average rate of change of T(r) over the interval [5,7] is 975 people per square mile.
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Define x:
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Let the tie be x
Tie = x
Shirt = x - 4.02
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Construct equation :
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The sum of the shirt and tie is $75.62
x + x -4.02 = 75.62
2x - 4.02 = 75.62
2x = 79.64
x = $39.82
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Find the cost of tie and shirt :
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Tie = x = $39.82
Shirt = x - $4.02 = $39.82 - $4.02 = $35.80
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Answer: The price of the short is $35.80
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