负4分之1加6分之5加3分之2减2分之1等于
问题描述：
负4分之1加6分之5加3分之2减2分之1等于
答
-1/4+5/6+2/3-1/2
=(5/6+2/3)-(1/4+1/2)
=(5/6+4/6)-(1/4+2/4)
=3/2-3/4
=6/4-3/4
=3/4