Start by looking at simplifying the smaller problems
anything to the power zero is 1

next apply the power of a power rule... multiply the powers

which becomes
Answer:
I think 20 is the answer of the question
The answer for question 4 is C and the answer for question 5 is D.
If it's 1/3 of an hour then we multiply it by 3 so 22.5 x 3 is 67.5
Answer: 67.5 m/h
The rest of the question is as following
What is the distance from person B to the top of the hill?
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Answer;
The attached figure represents the explanation of the problem.
So, it is required to find the distance BH
It will be calculated as following
∠A = 65° and ∠B = 80°
∴ ∠H = 180° - (65° + 80° ) = 35°
But the side AB = 45
So, we can use the sine rule to find the side BH



∴ BH ≈ 71.1 feet
∴ The distance from person B to the top of the hill ≈ 71.1 feet