Answer:

Step-by-step explanation:
We can rewrite the square root of negative 18 as
. We can evaluate these two quantities separately. The square root of 18 can be factored to get 3 squared times 2. We can take the 3 out to get
. Now, the square root of negative one can be rewritten as
, so this is equal to 
You didn't give enough information to answer the question.
We will make use of the concept of prime factors for solving this question. The prime factors of 1517 are:

So, as can be clearly seen the Niagara Fall tour operator can either sell 37 tickets for $41 each or 41 tickets for $37 each.
Now, we know that we cannot reach $37 using just three bills. Thus, the only option left to us is $41 which can be broken down into three bills of $20,$20 and $1. This satisfies our condition.
Thus the cost of a ticket was $41 and 37 such tickets were sold.
It's a six sided polygon. For any polygon the external angles add to 360 degrees. The internal angles shown are the supplements of the external angles. We have
(180 - θ₁) + (180 - θ₂) + ... + (180 - θ₆) = 360
6(180) - 360 = θ₁ + θ₂ + θ₃ + θ₄ + θ₅ + θ₆
720 = θ₁ + θ₂ + θ₃ + θ₄ + θ₅ + θ₆
The six angles add up to 720 degrees, and five of them add to
126+101+135+147+96=605
So y = 720 - 605 = 115
The degree sign is external to y so not part of the answer:
Answer: 115