Sums of sequences

Gemoetric sum

Arithmetic sum

Infinite sum

Σ

Σ

k=2

15

(2)(-4)*k-1

k=1

Σ

k=5

50

3k+1

n

2(0.2)^k-1

n

50-5+1=46

a1

an

3(5)+1=16

3(50)+1=151

S∞=a1/1-r=2/1-0.2

Sn

n(a1+an/2)

r <1

r >1

3841=

convergent

divergent(no sum)

r

15-2+1=14

-4

a1

(2)(-4)*2-1 = -8

Sn

a1(1-r*n)/(1-r)

=-429496731.2

done by: sara alsaed-halah algadi