Answer:

Step-by-step explanation:
We want to find the sum of

We can rewrite this as

This becomes;

Recall that;

This implies that;

Combine like terms:

I'm not sure what your book is saying about the matter but a cell phone is not usually an essential expense. If it is saying it is though, it would be an essential flexible expense.
It is B. Since each angle is 60 degrees, if you rotate B counterclockwise 6 times, it means that you rotated B 360 degrees. Therefore, the image of B would be B.