Yes, your answer are correct! There is a little work to be shown on number 1, but it isn't necessary.
Hope this helps! Brainliest it if it does!
Answer:
Only the second equation is an identity
Step-by-step explanation:

<u>Note that </u>

<u>You can confirm it: </u>

<u>Therefore</u>



<h2>
It is not an Identity</h2>
<u>Let's the second one</u>

In this case, we already performed the calculations, so it is true. It is an Identity.
To use the equation we need a1 and d(the common difference).
We have a1 = 57, we need to find d.
93-84 = 9; 84-75=9; 75-66=9; 66-57=9
d = 9
a350 = 57 + (350-1)(9)
a350 = 57 + (349)(9)
a350 = 57 + 3141
a350 = 3198
The correct answer is C. 4π / 3
Hope this helps!