Answer: -216
Step-by-step explanation:
To solve the exercise you must use the formula shown below:

Where:

You should find 
The formula to find it is:

Where d is the difference between two consecutive terms.

Then:

Substitute it into the first formula. Therefore, you obtain:

Answer:
c
Step-by-step explanation:
im 99% sure this is the answer
Answer:
A) 2x+5y
Step-by-step explanation:
I took the test.
Answer:
1
Step-by-step explanation:
As I have explained in the picture, all they are asking is for you to input 2 wherever there is an x.