1) -2/3-(-1/2)= -2/3+1/2=-4/6+3/6=-(4/6-3/6)=-1/6
2) 2/5-4/5= -(4/5-2/5)=-2/5
3) -3/8-5/8=-(3/8+5/8)=-8/8=-1
1) -2/3-(-1/2)= -2/3+1/2=-4/6+3/6=-(4/6-3/6)=-1/6
2) 2/5-4/5= -(4/5-2/5)=-2/5
3) -3/8-5/8=-(3/8+5/8)=-8/8=-1