Question

Due tomorrow help please

Answer 1

First differences are ...
41 -39 = 2
43 -41 = 2
45 -43 = 2
These are all the same, so 2 is the common difference of the arithmetic sequence beginning with 39.

The Nth term is

`a_(n)=a_(1)+(n-1)d\\a_(n)=39+2(n-1)\\a_(n)=37+2n`
The problem statement seems to ask for the 10th term and for a15. Here they are.

`a_(10)=37+2\cdot 10=57\\a_(15)=37+2\cdot 15=67`