5/6+3/4-1/3
=5/6-1/3+3/4
=5/6-2/6+3/4
=3/6+3/4
=1/2+3/4
=2/4+3/4
=1又1/4
5/6+3/4-1/3=10/12+9/12-4/12=(10+9-4)/12=15/12=5/4=1又1/4
5/6+3/4-1/3 =5/6-1/3+3/4 =5/6-2/6+3/4 =3/6+3/4
=6/12+9/12
=5/12