How do you find the next three terms of the arithmetic sequence 22, 20, 18, 16,...?

1 Answer
Apr 5, 2018

color(blue)(12,10,8)

Explanation:

The nth term of an arithmetic sequence is given by:

a+(n-1)d

Where:

bba is the first term.

bbd is the common difference.

bbn is the nth term.

If a,b,c are in arithmetic sequence, then:

b-a=c-b

This is called the common difference:

We have:

22,20,18,16,...

:.

20-22=18-20=-2

d=-2

First term is 20

a=20

We need 5th , 6th and 7th terms:

Using:

a+(n-1)d

5th=20+(5-1)(-2)=12

6th=20+(6-1)(-2)=10

7th=20+(7-1)(-2)=8

:.

22,20,18,16,color(blue)(12,10,8,)...