(2/15 + 1 7/12) * 30/100 - 2 : 2 1/4 * 9 30/2 + 2 1/3 = - 18 97/200
1) 2/15 + 1 7/12 = 8/60 + 1 35/60 = 1 43/60
2) 1 43/60 * 30/100 = 103/60 * 30/100 = 103/200
3) 2 : 2 1/4 = 2 : 9/4 = 2 * 4/9 = 8/9
4) 8/9 * 9 30/2 = 8/9 * 48/2 = 192/9 = 21 3/9 = 21 1/3
5) 103/200 - 21 1/3 = 103/200 - 64/3 = 309/600 - 12800/600 = - 12491/600 = - 20 491/600
6) - 20 491/600 + 2 1/3 = - 20 491/600 + 2 200/600 = - 18 291/600 = - 18 97/200