Hey friends
Find the sum of first 'n' even natural numbers. Hence find the sum of the first 20 even natural numbers.
please solve this with proper steps
The answer is n(n+1) and 420
Answers
Answered by
22
Answer :
The even Natural numbers are as follows -
2, 4, 6, 8, ...
So, the nth term be
= 2 + (n - 1)(2)
= 2 + 2n - 2
= 2n
So, the sum of first n even Natural numbers be
Sn
= n/2 (1st term + nth term)
= n/2 (2 + 2n)
= n (1 + n)
= n (n + 1) [Answer]
Hence, the sum of first 20 even Natural numbers be
S20
= 20 (20 + 1)
= 20 × 21
= 420 [Answer]
How to find nth term?
If a be the first term of an AP and d be the common difference, then the nth term be
tn = a + (n - 1)(d)
#MarkAsBrainliest
The even Natural numbers are as follows -
2, 4, 6, 8, ...
So, the nth term be
= 2 + (n - 1)(2)
= 2 + 2n - 2
= 2n
So, the sum of first n even Natural numbers be
Sn
= n/2 (1st term + nth term)
= n/2 (2 + 2n)
= n (1 + n)
= n (n + 1) [Answer]
Hence, the sum of first 20 even Natural numbers be
S20
= 20 (20 + 1)
= 20 × 21
= 420 [Answer]
How to find nth term?
If a be the first term of an AP and d be the common difference, then the nth term be
tn = a + (n - 1)(d)
#MarkAsBrainliest
Mia123456:
Hey i have a doubt in this step. n/2(2+2n)=n(1+n)? how? can you explain this step to me.thanks
ohk thank you so much...
Answered by
2
Answer:
l don't know you will say
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