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1995-1+2-3+4-5+… +1948-1949=______ ．
1995-1+2-3+4-5+… +1948-1949=1995-（1+1949+3+1947+… +975）+2+1948+4+1946+… +974 + 976 = 1995-975 × 975 + 975 × 974 = 1995-975 × (975-974) = 1995-975 = 1020
Math 1 * 2 * 3 * 4.1995
What are the last three digits of 1 * 2 * 3 * 4.1995?
Please give me your idea
It's all 0
Because many of these numbers end in zero
And zero times any number is zero
So there should be dozens of zeros in the end
1.2.3.4.5.6.7.8.9. Add +. -. *. /, become 1995
=(1+9)*(2+8)*(3+7)*(6-4)-5
(-1/2)^3+(-2)^2=
(-1/2)^3+(-2)^2
Original formula = - 1 / 8 + 4
=Three and seven eighties
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