Question

A. List the first six terms of the arithmetic sequence and identify the common

difference.
a₁ = 7
an = an-1 + 4
b. Find a15-
c. Find the sum of the first 15 terms in the sequence.

Answer 1

a1=7

an=an-1+4

a2=a2-1+4

a2=a1+4

a2=7+4

a2=11

a3=a3-1+4

a3=a2=+4

a3=11+4

a3=15

a4=a4-1+4

a4=a3+4

a4=19

a5=23

a6=27

a15=62

The common difference is 4.

The sum is 517.