find the sum of given below: 7+10+13+.....+46 . need full explanation
Answers
Answered by
2
Answer:
a=7
d=10-7
d=3
An=46
a+(n-1)d=46
7+(n-1)3=46
(n-1)3=39
n-1=39/3
n-1=13
n=14
Sn=n/2(a+An)
=14/2(7+46)
=7(53)
Sn=371
Answered by
1
Answer:
a=7
d=10-7=3
an=46
put the formula of an
a+(n-1)d=46
7+(n-1)3=46
(n-1)3=46-7
(n-1)3=39
(n-1)=39/3
n-1=13
n=13+1
n=14
Now,
Sn= n{a+an} divided by 2
Sn=14{7+46}/2
Sn=7(53)
Sn=371
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