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junior college 1 | H2 Maths
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not sure how to calculate the sum of the last k terms. thank you!
Date Posted: 7 years ago
Views: 546
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done
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clear
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The working is very standard and important for math problem solving. You need to visualize the terms. Write the first k terms and last k terms in 2 rows and align the terms neatly. Then subtract them vertically, you will find that the difference of each pair is the same, which is (n-k)d. And there are k such pairs. So the answer follows. Let me know if you need further explanation.
Date Posted:
7 years ago
thank you for clarifying!
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