2007/2008*2009用简便方法计算

1个回答

  • 2007/2008x2009

    =2007/2008x(2008+1)

    =2007/2008 x2008+2007/2008

    =2007又2007/2008

    2009分之2008*2008

    =2008/2009x2008

    =2008/2009x(2009-1)

    =2008/2009x2009-2008/2009

    =2008-2008/2009

    =2007又1/2009

    思路是把整数部分拆成含有负数中父母的形式,可以和父母约分,再用乘法分配律.

    不懂得继续问哦^_^