(1 3/4-2 3/8): 1 3/5= (8 1/3-10 1/2)*12/65=

(1 3/4 - 2 3/8) : 1 3/5 = (7/4 - 19/8) : 8/3 = ((14-19)/8) : 8/3 = -5/8 * 8/3 = -15
(8 1/3 - 10 1/2) * 12/65 = (25/3 - 21/2) * 12/65 = ((50-61)/6) * 12/65 = -11/6 * 12/65 = -22/65