Answer:
[tex]a_n=13.5-2.5n[/tex]
Step-by-step explanation:
[tex]11,\ 8.5,\ 6,\ 3.5,\ 1...[/tex]
[tex]So\ d=8.5-11=b-8.5=3.5-6=1-3.5[/tex]
[tex]=-2.5[/tex]
[tex]And\ a_1=\parallel \left\{Anithmetic\ \left.\ sequence\right\}\right.[/tex]
[tex]so\ a_n=a_1+d(n-1)[/tex]
[tex]=11-2.5(n-1)[/tex]
[tex]=13.5-2.5n[/tex]
[tex]The\ answer:a_n=13.5-2.5n[/tex]
I hope this helps you
:)
