Find a4 for the arithmetic series with s4=-36 and a1=9

ANSWER

The 4th term is -27

EXPLANATION

The sum of the first n-terms of an arithmetic sequence is

It was given that,

The n-term is given by:

We substitute n=4 to get,

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation:

step-by-step explanation: 4 cause 2+2=4