In an A.P, if d = 2, Sn= 49, T7 = 13 then find n.
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Answered by
3
Answer:
7
Step-by-step explanation:
✨d=2
Sn=49
A7=13
Sn=n/2(2a+(n-1)d)
A7=a+6d
13=a+12
✨a=1✨
now put this a in Sn equation.
49=n/2{2×1+(n-1)2}
98= n{2×1+(n-1)2}
98= n{ 2+2n-2}
98=2n²
n²= 49
:. n= 7
✨Value of n=7
Answered by
1
Answer:
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