Sn = 50
a = 5 d =1÷4
find n = ?
Answers
Answered by
2
Answer:
sn=n/2[2a+(n-1)d]
50=n/2[2×5+(n-1)4]
50=n/2[10+(n-1)4]
50(n-1)×4=n/2×10
50(n-1)×4=n×5
50/5=(n-1)×4
(n-1)×4=10
Similar questions