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IKMC 2009 - Grades 11-12 - Paper 01 - Self-study Question 15

IKMC · IKMC 2009 - Grades 11-12 - Paper 01 - Self-study

Question 15

What is the units digit of $1^2-2^2+3^2-4^2+\cdots-2008^2+2009^2$?
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