SOLUTION: 3, 8, 13, 18 ... find the 100th number

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Question 923402: 3, 8, 13, 18 ... find the 100th number
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
Arithmetic Sequence: d = 5
a%5Bn%5D+=+a%5B1%5D+%2B+%28n-1%29d
a%5B100%5D+=+3+%2B+%2899%295 = 498 Step I
.......
S%5Bn%5D=%28n%28a%5B1%5D%2Ba%5Bn%5D%29%29%2F2
S%5B100%5D=50%283+%2B+498%29 Step 2
.......
Re TY
complete the Calculation to find sum = 25,050
S%5B100%5D=50%283+%2B+498%29 = 25,050 Step 3
this is the way one would find the Sum regardless of the Number of terms.