Question

8th term of an arithmetic sequence is 53 and the 15th term is 102 find the common diffrence

Answer 1

a8=a+7d

53=a+7d. -----1

a15=a+14d

102=a+14d. ----2

subtract equation ---2 from ---1. we get.

53=a+7d

102=a+14d

- - -

-49= -7d

so,

d=7

hence, common difference is 7.