<span>7349 that's the answer and really? That was easy</span>
Answer:
He got 30 right!
Step-by-step explanation:
You can make some algebraic equations and solve it.
The first would be:

The second would be

You can then rearrange the second into

And subsitute it into the first like so:

After that, distribute the y into the parantheses.

Subtract the 21 on both sides and multiply by -1 on both sides:

You then can factor it into:

With Zero Product Property, we can determine y to be either -3 and 7. Since the variables are interchangable, you can say the same about x, just that whatever x is, y must be the other value.
Thus, the answer is 7 and -3.
The answer is C because the formula is 2 x pai x radius
Answer:
≈ -5.1857
≈ -5.4857
≈ 3.7262
Step-by-step explanation:
Rewrite the equation system as:



Now, write the system in its augmented matrix form:
![\left[\begin{array}{cccc}6&8&0&-75\\-3&6&6&5\\2&-9&0&39\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D6%268%260%26-75%5C%5C-3%266%266%265%5C%5C2%26-9%260%2639%5Cend%7Barray%7D%5Cright%5D)
applying row reduction process to its associated augmented matrix:
Swap R1 and R3, and then Swap R1 and R2:
![\left[\begin{array}{cccc}-3&6&6&5\\2&-9&0&39\\6&8&0&-75\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-3%266%266%265%5C%5C2%26-9%260%2639%5C%5C6%268%260%26-75%5Cend%7Barray%7D%5Cright%5D)
R3+2R1
![\left[\begin{array}{cccc}-3&6&6&5\\2&-9&0&39\\0&20&12&-65\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-3%266%266%265%5C%5C2%26-9%260%2639%5C%5C0%2620%2612%26-65%5Cend%7Barray%7D%5Cright%5D)
3R2+2R1
![\left[\begin{array}{cccc}-3&6&6&5\\0&-15&12&127\\0&20&12&-65\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-3%266%266%265%5C%5C0%26-15%2612%26127%5C%5C0%2620%2612%26-65%5Cend%7Barray%7D%5Cright%5D)
15R3+20R2
![\left[\begin{array}{cccc}-3&6&6&5\\0&-15&12&127\\0&0&420&1565\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D-3%266%266%265%5C%5C0%26-15%2612%26127%5C%5C0%260%26420%261565%5Cend%7Barray%7D%5Cright%5D)
Now we have a simplified system:


From (3):
(4)
Replacing (4) in (2)
(5)
Finally replacing (5) and (4) in (1)
