原式=(-1/2+3/2)-(5/4+1/4) =1-3/2 =-1/2
-1/2-5/4+3/2-1/4=(-1/2+3/2)+(-5/4-1/4)=1+(-3/2)=-1/2【俊狼猎英】团队为您解答
-1/2-5/4+3/2-1/4=-1/2+3/2-5/4-1/4=2/2-6/4=4/4-6/4=-2/4=-1/2
-1/2-5/4+3/2-1/4=(-1/2+3/2)-(5/4+1/4)= 1-1.5= -0.5
-1/2