(3 7/16:19 7/8 - 2/15)×0,9+17,17=
1) 3 7/16:19 7/8 =55/16:159/8=55/16*8/159=55/318
2) 55/318-2/15=(55*15-318*2)/4770=(825-636)/4770=189/4770=21/530
3) 21/530*0,9=21/530*9/10=189/5300
189/5300+17,17=189/5300+1717/100=(189+91001)/5300=91190/5300=17 109/530