2.87+5.6-0.87+4.4= 9/10-(+7/20)÷=

问题描述:

2.87+5.6-0.87+4.4= 9/10-(+7/20)÷=

2.87+5.6-0.87+4.4= (2.87-0.87)+(5.6+4.4)=2+10=12 9/10-(1/4+7/20)÷3/4=9/10-(1/4+7/20)÷15/20 =9/10-(1/4÷15/20+7/20÷15/20) =9/10-(5/15+7/15)=9/10-12/15=9/10-3/5=9/10-8/10=1/10