Hello,
We have to use this relation : 
He we have :

The total number of handshakes = 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 36
Answer: 36 handshakes
The books are $5, and the magazines are $10. I’m not sure which way you want it explained but since magazines are twice the price of books, you can solve the equation 3b + 2b = 25. This gives you b=5 which you just multiply by 2 giving you the price of a magazine.
Answer:
y = -2x - 3
Step-by-step explanation: