Answer: 21.9ft
Step-by-step explanation: please see attachment for explanation. Thanks.!
Answer: Choice D) 
The steps to finding the inverse will have us swap x and y. Afterward, we solve for y

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Extra info:
The inverse relation is not a function because of the plus minus. For instance, plugging x = 4 into
leads to y = -3 and y = 3 simultaneously. You would have to apply a domain restriction on
to make it a one-to-one function, to make the inverse a function. One possible domain restriction is
which would lead to the inverse function 