1. 5+1/5-2-1/6+4.8+4+5/6=5-2+4+4.8+0.2-1/6+5/6=12+2/3=12又3分之22. I-1/2+1/3-1/4I=I-6/12+4/12-3/12I=5/123. -1-1/2-4-1/4+2+1/3=-1-4+2-6/12-3/12+4/12=-3-5/12=-3又12分之5
