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2013!-(1!+2!x2+3!+4!x4+.+2011!x2011+2012!x2012)=

来源:学生作业帮 编辑:拍题作业网作业帮 分类:数学作业 时间:2024/04/28 05:42:46
2013!-(1!+2!x2+3!+4!x4+.+2011!x2011+2012!x2012)=
2013!-(1!+2!x2+3!x3+4!x4+.+2011!x2011+2012!x2012) (1)
=2013!-1!-2!x2-3!x3-4!x4-.-2011!x2011-2012!x2012
=2013!-2012!x(2013-1)-2011!x2011-.-4!x4-3!x3-2!x2-1!x1
=2013!-2013!+2012!-2011!x2011-.-4!x4-3!x3-2!x2-1!x1
=2012!-2011!x2011-.-4!x4-3!x3-2!x2-1!x1 (2)
=2012!-2011!x(2012-1)-2010!x2010-.-4!x4-3!x3-2!x2-1!x1
=2011!-2010!x2010-.-4!x4-3!x3-2!x2-1!x1 (3)
=2010!-2009!x2009-.-4!x4-3!x3-2!x2-1!x1 (4 ) (从1、2、3推出4)
.
=3!-2!x2-1!x1
=2!-1!x1
=1
过程、结果如上.