(5 7/10-4 8/15):2 2/3-3/8=
(5 7/10 - 4 8/15) / 2 2/3 - 3/8 = (57/10 - 68/15) / 8/3 - 3/8 = (171/30 - 136/30) / 8/3 - 3/8 = 35/30 / 8/3 - 3/8 = 7/16 - 3/8 = 7/16 - 6/16 = 1/16