SOLUTION: Two APs have the same common difference.The difference between their 100th term is100, what is the difference between their 1000th term?

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Question 696996: Two APs have the same common difference.The difference between their 100th term is100, what is the difference between their 1000th term?
Answer by god2012(113) About Me  (Show Source):
You can put this solution on YOUR website!
Let the first AP is represented as TA = a1 + (n1-1)d , where a is the first term and d is the common difference , n1 is the number of terms in AP1.
Let the second AP be represented as TB = a2 + (n2-1)d.
Now ,
100th term of TA is TA100 = a1 + 99d
Similarly, 100th term of TB is TB100 = a2+99d
TB100-TA100+=+%28a2-a1%29+=+100
Therefore , TA1000+-+TB1000+=+%28a2%2B999d%29-%28a1%2B999d%29
The difference is %28a2-a1%29+=+100