用简便方法计算:
(1)57.6*1.6+28.8*36.8-14.4*80(2)39*37-13*3^4(3)13.7*(17/31)+19.8*(17/31)-2.5*(17/31)(...
(1)57.6*1.6+28.8*36.8-14.4*80
(2)39*37-13*3^4
(3)13.7*(17/31)+19.8*(17/31)-2.5*(17/31)
(4)99又3/8乘以100又5/8 展开
(2)39*37-13*3^4
(3)13.7*(17/31)+19.8*(17/31)-2.5*(17/31)
(4)99又3/8乘以100又5/8 展开
1个回答
展开全部
(1)57.6*1.6+28.8*36.8-14.4*80
=28.8*(3.2+36.8-40)
=28.8*0
=0
(2)39*37-13*3^4
=39*37-39*4
=39*(3-4)
=39*33
=(40-1)*33
=1320-33
=1287
(3)13.7*(17/31)+19.8*(17/31)-2.5*(17/31)
=17/31*(13.7+19.8-2.5)
=17/31*31
=17
(4)99又3/8乘以100又5/8
=(100-5/8)(100+5/8)
=10000-25/64
=9999+1-25/64
=9999又39/64
=28.8*(3.2+36.8-40)
=28.8*0
=0
(2)39*37-13*3^4
=39*37-39*4
=39*(3-4)
=39*33
=(40-1)*33
=1320-33
=1287
(3)13.7*(17/31)+19.8*(17/31)-2.5*(17/31)
=17/31*(13.7+19.8-2.5)
=17/31*31
=17
(4)99又3/8乘以100又5/8
=(100-5/8)(100+5/8)
=10000-25/64
=9999+1-25/64
=9999又39/64
本回答被提问者采纳
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询