Question

find the sum
of 5+8+11+... to 10 terms using the formula

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Answer 1

Answer:

n=5/3

Step-by-step explanation:

a = 5

D = 3

an = 10

an=a+(n-1)d

10=5+3n-3

10=2+3n

5=3n

n=5/3

Answer 2

Answer:

160 is the answer !

Step-by-step explanation:

Here's the solution :-

Sn = n/2(a+(n-1)d)

n=10

a=5

d=3

Therefore ,

Sn = 10/2(5+(10-1)3)

Sn = 5(5+30-3)

Sn = 5×32

Sn = 160