用简便方法计算:2009/2010×2009 4/5×4+2/5×2+1/5×16

问题描述:

用简便方法计算:2009/2010×2009 4/5×4+2/5×2+1/5×16

2009/2010×2009
=2009/2010*(2010-1)
=2009-2009/2010
=2008又1/2010
4/5×4+2/5×2+1/5×16
=16/5+16/20+1/5*16
=1/5*16+1/20*16+1/5*16
=16*(1/5+1/20+1/5)
=16*9/20
=36/5(7.2)