Question

What is the missing term of the arithmetic sequence? 6, ______, 30

Answer 1

Let k = the constant amount added to the sequence since this is an arithmetic sequence

       x = missing number

You have to formulate an equation based on the sequence:

6 + k = x or k = x – 6

x + k = 30

Substitute the value of k to the second formula:

x + x – 6 = 30

2x = 36

x = 18

Therefore, the missing number is 18.