What is the iterative rule for the sequence: 10.5, 9, 7.5, 6, 4.5, 3, ...?

Hello,

Your sequence is arithmetic.

10.5-9=1.5

9-7.5=1.5

7.5-6=1.5

6-4.5=3

4.5-3=1.5

3-1.5=1.5

1.5-1.5=0

...

f (x) = f (n-1) - 1.5 is the iterative rule.

f (1) = 10.5

f (2) = 10.5-1.5=9

f (3) = 10.5-2*1.5=7.5

f (4) = 10.5-3*1.5=6

...

f (n) = 10.5-1.5 * (n-1) is the general form.