Question

Which of the following is the algebraic expression that best describes the sequence 7,14, 21, 28,?

Answer 1

`a_n=7n`

Explanation:

`"the terms are the terms of an "color(blue)"arithmetic sequence"`

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

`"where a is the first term and d the common difference"`

`a+(n-1)d" is the n th term"`

`"here "d=28-21=21-14=14-7=7`

`rArra_n=7+7(n-1)=7n`

`rArra_n=7n" generates the terms in the sequence"`