简便运算: (9-10)*(10-11)*(11-12)*…*(108-109);

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简便运算:(9-10)*(10-11)*(11-12)*…*(108-109);简便运算:(9-10)*(10-11)*(11-12)*…*(108-109);简便运算:(9-10)*(10-11)*

简便运算: (9-10)*(10-11)*(11-12)*…*(108-109);
简便运算: (9-10)*(10-11)*(11-12)*…*(108-109);

简便运算: (9-10)*(10-11)*(11-12)*…*(108-109);
解:
(9-10)*(10-11)*(11-12)*…*(108-109);
=(-1)(-1)(-1)(-1)...(-1)
=(-1)^(108-9+1)
=(-1)^100
=1

(9-10)*(10-11)*(11-12)*…*(108-109)
=-1*(-1)*(-1)*(-1)*....(-1)
=1