Missing part of the question
Determine the number of handshakes, i, that will occur for each number of people, n, in a particular room. (people)
Answer:

Step-by-step explanation:
Given
For 5 people

Using the given instance of 5 people, the number of handshakes can be represented as:

The above sequence is an arithmetic sequence and the total number of handshakes is the sum of n terms of the sequence.

Where
--- The first term
--- The last term
So:


(5ab-4a-8)-(9ab-5)
Ok just remember that the minus sign before the (9ab-5) is like a minus 1 so it changes the sign inside the bracket...
>>5ab-4a-8-9ab+5
>>-4ab-4a-3
I'm guessing you just have to leave it like that unless there are other parts to the question or whatever but that's that simplified as far as it can be!
Where the question? you didn’t show the question to fill in the blanks