(7/15+3/10)*2 14/23+ 1 6/57:(7/9-30/57)=
( 2*7/30 + 3*3/30 ) * 60/23 + 63/57 : (7/9-30/57) = (14/30+9/30) * 60/23 + 63/57:7/9 - 63/57:30/57) = 23/30 * 60/23 + 63/57*9/7 - 63/57 * 57/30= 2+(9*9)/57 - 63/30=
2+81/57-21/10=2-21/10+1 24/57=2-21*57/570+ 24*10/570= 2- 1197/570 +240/570= 2-957/570=
2-319/190= 2- 1 129/190= 61/190