My teacher ask us to do this two odd questions,Idk how to use the formulas

Question

Can someone use them as example:
Quest1:( 1 x 3 ), (2 x 4 ), (3 x 5 )
Formula:[n x (n+2)]
Quest2:1/2 ,2/3 ,3/4 ,4/5
Formula:n/n+1

Answer 1

I suppose you want the next term in the series although you don't day that.
Quest1:( 1 x 3 ), (2 x 4 ), (3 x 5 )
Formula:[n x (n+2)]
So the next term after 3 x 5 is
n = 4, then 4 + 2 = 6 and te next term is 4 x 6
next term is n = 5 so n + 2 = 7 and the term is
5 x 7 etc. I think the idea here is to calculate something other than the next term. So what would it be for n = 10?
Then n + 2 = 12 and the term would be 10 x 12.
The second part is done the same way.