Ответ:

Объяснение:

1)  x+7 8/9 = 9 7/12;

x=9 7/12 - 7 8/9;  => НОК(12;9) = 36;

x=9 21/36 - 7 32/36;

x=2 (21-32)/36;

x= 1 (36+21-32)/36;

x=1 25/36.

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2)  x-7 8/19 = 4 35/38;

x= 7 8/19 + 4 35/38; =>НОК(19;38) = 38 =>

x=7 16/38 + 4 35/38;

x=11 (16+35)/38;

x=11 51/38;

x=12 13/38.

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1)  8 1/4 - 5 1/2 = 8 1/4 - 5 2/4 = 3 (1-2)/4 = 2(4+1-2)/4 = 2 3/4;

2)  7 4/15 - 4 3/5 = 7 4/15 - 4 9/15 = 2 (15+4-9)/15 = 2 10/15 = 2 2/3;

3)  12 2/5 - 5 3/4 = 12 8/20 - 5 15/20 = 6 (20+8-15)/20 = 6 13/20;

4)  6 3/10 - 4 7/15 = 6 9/30 - 4 14/30 = 1 (30+9-14)/30 = 1 25/30 = 1 5/6;

5)  9 5/18 - 1 7/12 = 9 10/36 - 1 21/36 = 7 (36+10-21)/36 = 7 25/36;

6)  8 7/15 - 2 17/18 = 8 42/90 - 2 85/90 = 5 (90+42-85)/90 = 5 47/90;

7)  8 2/3 - 7 5/7 = 8 14/21 - 7 15/21 = (21+14-15)/21 = 20/21;

8)  7 3/16 - 1 5/24 = 7 9/48 - 1 10/48 = 5 (48+9-10)/48 = 5 47/48.