Question

Find the fourth term of an arithmetic sequence if the first term is 12 and the common difference is -3. A (subscript 4)=???

Answer 1

The fourth term of the sequence is 3

Explanation:

For an nth term in an arithmetic sequence

A(n) = a + (n - 1)d

Where n is the number of terms

a is the first term

d is the common difference

From the question

a = 12

d = - 3

So the fourth term of the sequence is

A(4) = 12 + (4 - 1)-3

= 12 + (3)(-3)

= 12 - 9

The final answer is

3

Hope this helps you.