( 2 7\15 -5\12 ) * 5\6

(2_7/15-5/12)*5/6=(37/15-5/12)*5/6=((37*4-5*5)/60)*5/6=((148-25)60)*5/6= 
123/60*5/6=41/24=1_17/24

(2 7/15 - 5/12) * 5/6 = (37/15 - 5/12) * 5/6 = (148-25)/60 * 5/6 = 123/60 * 5/6 = 123/72 = 1 51/72 = 1 17/24