Question

помогите решить примеры номер 750

Answer 1

1) 3/7 + 5/14 = 6/14 + 5/14 = 11/14
2) 2 1/8 + 3 5/12 = 17/8 + 41/12 = 51/24 + 82/24 = 133/24 = 5 13/24
3) 6 15/21 + 2 9/14 = 141/21 + 37/14 = 47/7 + 37/14 = 94/14 + 37/14 = 131/14 = 9 5/14
4) 5 13/15 + 1 7/12 = 88/15 + 19/12 = (88×4)/60 + (19×5)/60 = 352/60 + 95/60 = 447/60 = 149/20 = 7 9/20
5) 1 - 9/11 = 11/11 - 9/11 = 2/11
6) 8/9 - 7/12 = (8×4)/36 - (7×3)/36 = 32/36 - 21/36 = 11/36
7) 8 - 5 4/9 = 3 - 4/9 = 2 5/9
8) 7 3/8 - 3 5/6 = 4 3/8 - 5/6 = 35/8 - 5/6 = (35×3)/24 - (5×4)/24 = 105/24 - 20/24 = 85/24 = 3 13/24
9) 3/8 × 2/9 = 1/4 × 1/3 = 1/12
10) 2 1/10 × 1 1/14 = 21/10 × 15/14 = 3/2 × 3/2 = 9/4 = 2 1/4
11) 1 3/7 ×14 = 10/7 × 14/1 = 10/1 × 2/1 = 20
12) 3 3/5 × 1 1/9 = 18/5 × 10/9 = 2/1 × 2/1 = 4
13) 5/9 : 10/27 = 5/9 × 27/10 = 1/1 × 3/2 = 3/2=1½
14) 5/7 : 3/8 = 5/7 × 8/3 = 40/21 = 1 19/21
15) 4 4/9 : 2 2/3 = 40/9 : 8/3 = 40/9 × 3/8 = 5/3 × 1/1 = 1⅔