5又4分之1-【9又2分之1减(14x50分之7加3.4)】除以3
=5又4分之1-【9又2分之1减(1.96加3.4)】除以3
=5又4分之1-【9.5减5.36】除以3
=5又4分之1-4.14除以3
=5.25-1.38
=3.87