2. Find the sum of the 7th term of the geometric series. 3+1+1/3+ ...
How do I find it, must show work

sum

In the given G.S., we have,

a

=

the

1

s

t

term

=

3

,

& the common ratio

r

=

−

6

3

=

−

2

Hence, the sum

S

n

of its first

n

terms is given by,

S

n

=

a

(

1

−

r

n

)

1

−

r

∴

The Reqd. Sum S_7

=

3

(

1

−

(

−

2

)

7

)

1

−

(

−

2

)

=

3

(

1

+

128

)

3

=

129

answer: 48

just remember to use pemdas:

parentheses

expressions

multiplication

division

addition

subtraction

its a straight line parallel to the time axis