简算:(9991*1999.1999+9991.9991*1999)/2.0002=
问题描述:
简算:(9991*1999.1999+9991.9991*1999)/2.0002=
答
(9991*1999.1999+9991.9991*1999)/2.0002
=(9991*1999*1.0001+9991*1.0001*1999)/2.0002
=1.0001(9991*1999+9991*1999)/2.0002
=1.0001*2*9991*1999/2.0002
=9991*1999
=19972009