8.4÷0.6= 3.6×4÷3.6÷4= 0.32= 0.6b+0.4b=
7.14÷0.7= x+5.2x= 5.4×101-5.4= y-0.4y-0.3y=
2.5×40= 0.63÷0.7= 5.7+4.23= 42=
5.8×5= 1- = 1- = 63=
8.1÷0.9= 7.2÷4= 1.25×8= + =
4.3×0.7= 2+ = 10+3.28×0= 3.2×1.2÷3.2×1.2=
- = 0.75+ =
×2.7=
2008年夏季奥运会和2022年冬季奥运会的成功举办使北京成为首个“双奥之城”。