(1/4+2/3)•6/11 ——————— (3/4-1/3):5/9
(1/4 +2/3)•6/11= (3/12+8/12)•6/11= 11/12•6/11=1/2 (3/4-1/3):5/9=(9/12-4/12):5/9= 5/12:5/9=5/12•9/5=3/4