15 3/8 : (2 75/100x + 5 5/6) - 1 1/2 = 3/4

15 3/8 / (2 75/100 х + 5 5/6) - 1 1/2 = 3/4
123/8 / (275/100 *х +35/6) - 3/2 = 3/4        123/8 / ( 11/4 *х +35/6) =3/4 +3/2
123/8 / (11/4*х +35/6 ) = 9/4       123/8 = 9/4 * (11/4 *х +35/6 )
123/8 = 99/16 *х +105/8          123/8 - 105/8 = 99/16 *х         18/8 = 99/16*х
х = 4/11