8.7*9.9簡算

8.7*9.9簡算


8.7*9.9
=8.7x(10-0.1)
=8.7x10-8.7x0.1
=87-0.87
=86.13
不懂的還有追問



7.09*10.8-0.8*7.9簡算
如題.
一刻鐘內回答追5懸賞
貌似誤了……


7.09*10.8-0.8*7.9
=76.572-6.32
=70.252
此題不能用簡算,你抄錯題了,應為:
7.09*10.8-0.8*7.09
=7.09*(10.8-0.8)
=70.9
不信自己好好看看題.



(313+5/6+7/8+9/10)/(5/6+7/8+9/10)怎麼簡算?


(313+5/6+7/8+9/10)/(5/6+7/8+9/10)
=313+(5/6+7/8+9/10)/(5/6+7/8+9/10)
=313+1
=314