4 5/12-3 7/18) : 9,25+5/6 / (0,4+1/8+0,75) * 2/3

4 5/12 - 3 7/18 = 53/12 - 61/18 = (159 - 122) / 36 = 37/36

37/36 : 9 25/100 = 37/36 * 100/925 = 3700 / 33300 = 37/333

37/333 + 5/6 = (74 + 555) / 666 = 629/666

4/10 + 1/8 = (20 + 5) / 40 = 25/40 = 5/8

5/8 + 75/100 = (250 + 300) / 400 = 550/400 = 55/40

55/40 * 2/3 = 110/120

629/666 : 110/120 = 629/666 * 120/110 = 8280 / 73260 = 828/7326 = 138/1221