If you visualize the problem, there are two concentric circles, the pool, and the pool plus the walkway. So, we have to subtract the area of these two concentric circles to find the walkway.
Bigger circle: Pool plus walkway
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diameter = 18 + 4(2) -- this is because there is 2 ft of walkway at each far end
diameter = 26 ft
Area = pi*(26/2)^2
Area = 530.93 ft2
Smaller circle:pool
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diameter = 18 ft
Area = pi*(8/2)^2
Area = 50.27 ft2
Area of walkway
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A = 530.93 - 50.27
A = 480.66 ft2
Then the cost would be
Cost = $4.25 * 480.66
Cost = $2,042.81
For the first one it is 5 x10^{8}
and for the second one it is 0.0005 = 5 × 0.0001 = 5 × 10−4
The scientific notation:


Used:

Answer: (4 × 10⁸)² = 1.6 × 10¹⁷
True because if you did 180°-270° it would be in quadrant 3 or it could be on quadrant 2 because quadrant 2 is 90-180
Answer: b
b represents a function because every x value only has one y value/output