一个是：0.28×8.6＋7.2×0.86 还有一个是：999×778＋333×666

分类: 作业答案 • 2022-05-21 10:18:16

问题描述：

一个是：0.28×8.6＋7.2×0.86
还有一个是：999×778＋333×666

答

0.28×8.6＋7.2×0.86
=0.28×8.6＋0.72×8.6
=(0.28＋0.72)×8.6
=8.6
999×778＋333×666
=999×778＋999×222
=999000

答

0.28*(8.6*0.1)+(7.2*0.1)*0.86
=0.28*0.86+0.72*0.86
=(0.28+0.72)*0.86
=0.86
第一题

答

0.28×8.6＋7.2×0.86
=0.28×8.6＋0.72×8.6
=(0.28＋0.72)×8.6
=1×8.6
=8.6
999×778＋333×666
=999×778＋999×222
=999×（778+222）
=999×1000
=999000