Question

Write the explicit rule for this arithmetic sequence 9,12,15,18…

Question 3 options:


an=9+(n−1)3, an=3n+6



an=18+(n−1)9, an=9n+9



an=3+(n−1)9, an=9n−6



an=9+(n−1)4, an=4n+5

Answer 1

an=9+(n−1)3, an=3n+6

Explanation:

Arithmetic Sequence:

d=3

This is the formula of an arithmetic sequence.

an=a1+d(n−1)

Step 1: Substitute in the values of

a1=9 and d=3.

an=9+(3)(n−1)

Step 2: Simplify each term.

an=9+3n−3

Step 3: Subtract 3 from 9.

an=3n+6

Answer 2

the answer is an=9+(n−1)3, an=3n+6