ok so I have to create an equation to explain how many handshakes you get if you input any number of people. for instance, i came up with this equation:

n=number of people

n(n-1)

-------

2

so we know it would take 15 handshakes for 6 people to all shake everyones hand...and 21 for 7 people, and 28 for 8 people and 36 for 9 people and so on. so when you put 7 in as n, you get 42, then you divide by 2 and get 21, which is the number of handshakes.

but the other part of the problem is that the equation has to be manipulated to be true for (x+1)

therefore; (x+1)((x+1)-1)

-----------------

2

kind of like that. except for that then it isn't true. so i have to manipulate an equation to be true for x=1 and x=x+1

which is causing a serious problem

and i have to show how i manipulated it to get there.

so if anyone can help, please do!!

thanks!