Using the fundamental counting theorem, we have that:
- 648 different area codes are possible with this rule.
- There are 6,480,000,000 possible 10-digit phone numbers.
- The amount of possible phone numbers is greater than 400,000,000, thus, there are enough possible phone numbers.
The fundamental counting principle states that if there are p ways to do a thing, and q ways to do another thing, and these two things are independent, there are ways to do both things.
For the area code:
- 8 options for the first digit.
- 9 options for the second and third.
Thus:

648 different area codes are possible with this rule.
For the number of 10-digit phone numbers:
- 7 digits, each with 10 options.
- 648 different area codes.
Then

There are 6,480,000,000 possible 10-digit phone numbers.
The amount of possible phone numbers is greater than 400,000,000, thus, there are enough possible phone numbers.
A similar problem is given at brainly.com/question/24067651
Answer:
Which i think is the first one, there may just be a typing error.
Step-by-step explanation:
A polynomial of order n has the following format:

In which a is the leading coefficient,
are the roots.
If a root appears m times, they are said to have multiplicity m.
Leading coefficient of 1 and roots 21 and 31 with multiplicity 1

So the correct answer is:

Which i think is the first one, there may just be a typing error.
The final angle has an angle measure of 115 degrees.
I believe also 115 degrees bc they’re vertical angles