Can you please help me I don't understand
1 answer:
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Answer:
c. 2.4 yards
Step-by-step explanation:
If x is the width of the walkway, then the total landscape area is ...
(4.5 +x)(7.5 +x) = 68.31
This quadratic equation can be rearranged to standard form and solved in any of the usual ways.
(x +4.5)(x +7.5) -68.31 = 0
x² +12x -34.56 = 0
Using the quadratic formula, we have ...
x = (-12 ±√(12² -4(1)(-34.56)))/2 = -6 ± √70.56 = -6 ± 8.4
The positive solution is x = 2.4.
The width of the walkway is 2.4 yards.
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A graphing calculator or spreadsheet solver can also find the solution for you.
Answer:
36.50$
Step-by-step explanation:
The power of the light bulb in this problem is
P = 100 W = 0.1 kW
And the light bulb is operated for a time of
t = 10 hours
per day.
The light bulb is operated over 1 year (365 days), so the number of hours of operation is:
So the total energy consumed by the light bulb is
We know that the cost of operation is
p = 10 cents/kWh
Therefore, the total cost will be:
So, 3650 cents, or 36.50$.