1) 7/9 + 5/6 - 2 7/12 = 7/9 + 5/6 - 31/12 = 7/9 + 10/12 - 31/12 = 7/9 - 21/12 = 7/9 - 7/4 = 28/36 - 63/36 = -35/36;
2) 28/33 * 45/98 : 2 3/11 = 28/33 * 45/98 : 25/11 = 28/33 * 45/98 * 11/25 = 2/3 * 9/7 * 1/5 = 2 * 3/7 * 1/5 = 6/35;
3) 5(3+3x) - 2(12-8x) = 15 + 15x - 24 + 16x = 31x - 9;
1) 7/9 + 5/6 - 2 7/12 = 7/9 + 5/6 - 31/12 = 7/9 + 10/12 - 31/12 = 7/9 - 21/12 = 7/9 - 7/4 = 28/36 - 63/36 = -35/36;
2) 28/33 * 45/98 : 2 3/11 = 28/33 * 45/98 : 25/11 = 28/33 * 45/98 * 11/25 = 2/3 * 9/7 * 1/5 = 2 * 3/7 * 1/5 = 6/35;
3) 5(3+3x) - 2(12-8x) = 15 + 15x - 24 + 16x = 31x - 9;