Question

How do I solve this problem?

Answer 1

21, 18, 15

Explanation:

First term = a1

Second term = a2

Third term = a3

a1 = 21

a2

= a + d

= 21 - 3

= 18

a3

= a + 2d

= 21 + 2 ( - 3 )

= 21 - 6

= 15

The first 3 terms are 21, 18, 15.