It's C. In order to be in standard form you have to have all your exponents in descending order. They don't all have to be there in order, the ones that are just have to go from highest to lowest.
Answer:
point-slope form: 
Step-by-step explanation:
hope this helps :)
The reflection across the x-axis only change the signal of the y coordinate. Hence, the new point is

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16,896 feet is the distance
R=1/2*d
r=1/2*9
r=4.5 inches