(+2/3)*(负一又二分之一)*(负二又三分之一)*(-3/5),
问题描述：
(+2/3)*(负一又二分之一)*(负二又三分之一)*(-3/5),
答
+2/3×（-3/2)×（-7/3)×（-3/5)= [+2/3×（-3/2)]×[（-7/3)×（-3/5) ]=-1×7/5=-7/5
答
=2/3*(-3/2)*(-7/3)*(-3/5)
=-(2/3*3/2)*(7/3*3/5)
=-1*7/5
=-7/5