Question

sigma 40/ r=2 (2r +1)​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

Let S=∑

r=1

n

{(2r−1)a+

b

r

1

}

⇒S=2a∑

r=1

n

r−a∑

r=1

n

+∑

r=1

n

(

b

r

1

)

⇒S=an(n+1)−an+

b

1

[

(1/b)−1

(1/b)

n

−1

]

⇒S=an

2

+

b

n

(b−1)

b

n

−1