find the sum of first
20 terms of AP 3, 7, 11, 15 using the formula
Answers
Answered by
7
Answer:
820
Step-by-step explanation:
a = 3
d = 4
S = n/2[2a+(n-1)d]
S = 10[6+19×4]
S = 820
Answered by
1
Answer:
Step-by-step explanation:
T1=a=3,d=5 tn=20
Formula=tn=a+(n-1)d
=20=3(20-1)5
=20=285
=285-20
=265
tn=265
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