3: 315-(79+15) =315-15-79 =300-79 =221
45x0.99=45x(1-0.01)
=45x1-45x0.01
=45-0.45
=44.55
25x25x16 =(25x4)x(25x4) =100x100 =10000720÷5÷6
=720÷(5x6)
=720÷30
=24
720÷5÷6 540÷45 =540÷9÷5 =60÷5 =129/7-(3/4-1/8)-3/8=9/7-3/4-(3/8-1/8)=9/7-(3/4+1/4)=9/7-1=2/7本答案出自零五网网网址:https://www.05wan |