-1 + 3-5 + 7-9 + 11... - 1997 + 1999 how to calculate the formula | Math enthusiast | Mathematical art

-1 + 3-5 + 7-9 + 11... - 1997 + 1999 how to calculate the formula

-1+3-5+7-9+11...-1997+1999
=(-1+3)+(-5+7)+(-9+11)+...+(-1997+1999)
=2 + 2 + 2 +... + 2 (500 pieces of 2)
=1000

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