简便运算:1,9.42*10-94.2*0.9 2,3.61/(7.2-5.3)*25 3,1.58/ [20-(5.4+6.7)] 4,2.4*1.5+.6/1.5

问题描述:

简便运算:1,9.42*10-94.2*0.9 2,3.61/(7.2-5.3)*25 3,1.58/ [20-(5.4+6.7)] 4,2.4*1.5+.6/1.5

1,9.42*10-94.2*0.9 =9.42*(10-9)=9.422,3.61/(7.2-5.3)*253.61/1.9*25=1.9*25=(2-0.1)*25=50-2.5=47.53,1.58/ [20-(5.4+6.7)]=1.58/【20-(5.4+6.6+0.1)】=1.58/【8-0.1】=0.24,2.4*1.5+.6/1.5=1.5*(2.4+...第二题是:3.61/(7.2-5.3)*25第二题是:3.61/【(7.2-5.3)*25】=3.61/(1.9*25)=3.61÷(1.9*25)=3.61÷1.9÷25=1.9÷25=(1.9*4)÷(25*4)=7.6÷100=0.076