如题所述
9.9÷0.5÷2.2
=9×1.1÷0.5÷(2×1.1)
=9×1.1÷0.5÷2÷1.1
=9÷0.5÷2×1.1÷1.1
=9÷(0.5×2)×(1.1÷1.1)
=9÷1×1
=9
——————————————————
=9.9÷2.2÷0.5
=(9.9÷1.1)/(2.2÷1.1)÷1/2
=9/2×2/1