Question

. Find the sum of the two middle most terms of theAP: -4/3,-1,-2/3......,4 1/3

Answer 1

Step-by-step explanation:

=

3

1

d=

3

2

−

2

1

=

3

1

T

n

=a+(n−1)d

3

20

=

3

1

+(n−1)

3

1

20=1+(n−1)

20=1+n−1

20=n

Middle terms t=10,t=11

T

10

=

3

1

+(10−1)

3

1

T

10

=

3

1

+9(

3

1

)

T

10

=

3

10

T

11

=

3

1

+(11−1)

3

1

T

11

=

3

1

+10(

3

1

)

T

11

=

3

11

T

10

+T

11

=

3

10

+

3

11

=

3

21

=7