高考问答小学生安全自护顺口溜:求教(数学六年级)~~~~~~~~~~~
来源：百度文库 编辑：高考问答 时间：2024/05/04 04:12:26
(1997*0.3)/(1999*0.5)+(1.2/1999)=?(要写过程)
(1997*0.3)/(1999*0.5)+(1.2/1999)
=(1997*0.3)/(1999*0.5)+(0.6/1999*0.5)
=[(1997+2)*0.3]/(1999*0.5)
=0.6
1997*0.3)/(1999*0.5)+(1.2/1999
=1997*0.3*2/1999+1.2/1999
=1997*0.6/1999+1.2/1999
=[1997+2]*0.6/1999
=1999*0.6/1999
=0.6
(1997*0.3)/(1999*0.5)+(1.2/1999)=(1997*0.3*2)/1999+(1.2/1999)=(1997*0.3*2+1.2)/1999=[0.6*(1997+2)]/1999=(0.6*1999)/1999=0.6
0.5=1/2,*0.5也就等同除以2，这样分母就相同了，可以加在一起，然后是提取0．6，这样结果就出来了
1997*0.3)/(1999*0.5)+(1.2/1999
=1997*0.3*2/1999+1.2/1999
=1997*0.6/1999+1.2/1999
=[1997+2]*0.6/1999
=1999*0.6/1999
=0.6
这样结果就出来了