80-12×4÷3 60+180÷20-5 4.5-(2.68+0.86)
15.37-2.8-2.2 19.92+10.35-9.92 42×4×25
要用递等式
追答80-12×4÷3=80-(12÷3)×4=80-16=64
60+180÷20-5=60+9-5=64
4.5-(2.68+0.86)=4.5-3.54=0.96
15.37-2.8-2.2=15.37-(2.8+2.2)=15.37-5=10.37
19.92+10.35-9.92=19.92-9.92+10.35=10+10.35=20.35
42×4×25=42×(4×25)=42×100=4200
递等式
追答答案仅供参考....