(负1又2分之1)/(+4分之3)*(负0.2)*1又4分之3/1.4*(负5分之3)
=-3/2*4/3*0.2*7/4*5/7*3/5
=-(3/2*4/3)*(0.2*3/5)*(7/4*5/7)
=-2*3/25*5/4
=-3/10