Answer: Choice D) 
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Work Shown:
Explanation:
First I subtracted y/b from both sides. Then I multiplied both sides by 'a' to fully isolate x. You can optionally distribute the 'a' through to each term inside the parenthesis, but your teacher has chosen not to do this.
consider X-axis along the east-west direction and north-south direction along Y-axis
A = magnitude of distance traveled by hiker in north-east direction = 30 kilometer
θ = angle of direction of displacement of the hiker relative to x-axis or east direction = 45 degree counterclockwise
A' = component of distance traveled by the hiker along the east direction.
Since the angle is given with the x-axis, the Sin provides the component in Y-direction. hence
Using the equation
A' = A Sinθ
Inserting the values
A' = (30) Sin45
A' = 21.2 km
I pretty sure the answer is 3.2 hours. I'm not completely sure though....
When you multiply 205 by 0.91 you get 186.55 and 205 minus 186.55 is 18.45
