Question

10 th term of an arithmetic sequence is 36 what is the sun of first term and 19th term? ​

Answer 1

Answer:

1st term : t1

10th term : t10

19th term : t19

let A.P series be

a,a+d,a+2d,....,a+(n-1)d

so,1st term (t1) =a

10th term (t10) = a+(10-1)d=a+9d

19th term (t19) = a+18d