Question

a=5, d=3, an=50 find n and sn
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Answer 1

Step-by-step explanation:

a=5, d=3 , an= 50

find n and sn.

an = 50

=> 5n = 50

=> n = 10

Answer 2

n=16

sn=440

Step-by-step explanation:

an=a+(n-1)d

50=5+(n-1)3

50=5+3n-3

50=2+3n

2+3n=50

3n=50-2

3n=48

n=48/3

n=16

sn=n/2(a+an)

sn=n/2(a+an)s16=16/2(5+50)

sn=n/2(a+an)s16=16/2(5+50)=8×55

s16=440