Step-by-step explanation:
i wish I could help but no idea
Answer:
8 + 18+ 28+ 38+ 48= 140
Step-by-step explanation:
Answer:

Step-by-step explanation:
Let the quadratic function be

We substitute
into the equation to obtain;


We substitute
to obtain;


We finally substitute
to obtain;


We put equation (2) into equation (1) to get;





We add equation (4) and (5) to get;



We put
into equation (5) to get;



The reqiured quadratic function is

If an is a5
and
an-1 is a4
then using your recursive formula for an arithmetic sequence
an=an-1 +d
then
a5=a4+d
now, a4 =6 and common difference "d" is d=-11
hence
a5=6 -11
6-11= -5
any questions?