It is given that 13, 17, 21, 25,... is an arithmetic sequence

Find the general term Tn of the sequence.

Find the 10th term of the sequence.

It is given that 13, 17, 21, 25,... is an arithmetic sequence

Find the general term Tn of the sequence.

Find the 10th term of the sequence.

17-13=4

21-17=4

So the series is an arithmetic sequence with common difference 4, a_1=13

The general term for the sequence is

T_n=a_1+(n-1)d=13+4(n-1)

=4n+7

When n=10,

T_{10}=4\times 10+7= 21