The rate of change of stamp collection was $57.5 per year.
Rate is comparison of two related quantities.
Often the second quantity is time (per second, per hour, etc) but it can be anything.
Can be in the style "this per that" or as a single number calculated using division.
Example: Sam makes 3 pancakes every 6 minutes, that is a rate of:
• 3 pancakes per 6 minutes
• 0.5 pancakes per minute
• 30 pancakes per hour
• an hourly rate of 30
By formula the rate of change = Change in cost/ Time taken
=( $980 - $420)/ 8years
= $460/ 8 years
= $57.5 per year
Thus the rate of change of stamp collection was $57.5 per year.
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Answer:
Step-by-step explanation:
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Answer:
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Answer:
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Answer:
diameter of the pizza = 21.88 centimeters
Step-by-step explanation:
Given:
C = d^2 – 2d + 447
where
C = cost of the pizza
d = diameter of the pizza
If the pizza costs $12.00, then what is a reasonable estimate for the diameter of the pizza?
12 = d^2 – 2d + 447
d^2 - 2d = 447 - 12
d^2 - 2d = 435
d^2 - 2d - 435 = 0
Solve the quadratic equation using formula
a = 1
b = -2
c = -435
d = -b +or- √b^2 - 4ac / 2a
= -(-2) +or- √(-2)^2 - (4)(1)(-435) / 2(1)
= 2 +or- √4 - (-1740) / 2
= 2 +or- √4 + 1740 / 2
= 2 +or- √1744 / 2
= 2 +or- 4√109 / 2
= 2/2 +or- 4√109/2
= 1 +or- 2√109
d = 1 + 2√109 or d = 1 - 2√109
= 1 + 2(10.44) or d = 1 - 2(10.44)
= 1 + 20.88 or d = 1 - 20.88
d = 21.88 or -19.88
diameter of the pizza = 21.88 centimeters
Therefore, the estimated diameter of the pizza can not be negative. So, diameter of the pizza = 21.88 cm