23 2/5+х=4 5/6+21 1/6х+19 3/7=5 7/12+ 16 5/12х+6 1/4=17 2/3-5 2/34

23 2/5 + х = 4 5/6 + 21;

117/5 + х = 29/6 + 21;

117/5 + х = (29 * 1 + 21 * 6)/6;

117/5 + х = (29 + 126)/6;

117/5 + х = 155/6;

х = 155/6 - 117/5;

х = (155 * 5 - 117 * 6)/30;

х = (775 - 702)/30;

х = 73/30;
х = 2 13/30.

Ответ: 2 13/30.

1/6х + 19 3/7 = 5 7/12 + 16;

1/6х + 19 3/7 = 67/12 + 16;

1/6х + 19 3/7 = (67 * 1 + 16 * 12)/12;

1/6х + 19 3/7 = (67 + 192)/12;

1/6х + 19 3/7 = 259/12;

1/6х = 259/12 - 19 3/7;

1/6х = 259/12 - 136/7;

1/6х = (259 * 7 - 136 * 12)/84;

1/6х = (1813 - 1632)/84;

1/6х = 181/84;

х = 181/84 : 1/6;

х = 181/84 * 6/1;

х = 181/14;

х = 12 13/14.

Ответ: 12 13/14.

5/12х + 6 1/4 = 17 2/3 - 5 2/34;

5/12х + 6 1/4 = 53/3 - 172/34;

5/12х + 6 1/4 = (53 * 34 - 172 * 3)/102;

5/12х + 6 1/4 = (1802 - 516)/102;

5/12х + 6 1/4 = 1286/102;

5/12х + 6 1/4 = 643/51;

5/12х = 643/51 - 6 1/4;

5/12х = (643 * 4 - 25 * 51)/204;

5/12х = (2572 - 1275)/204;

5/12х = 1297/204;

х = 1297/204 : 5/12;

х = 1297/204 * 12/5;

х = 1297/17 * 1/5;

х = 1297/85;

х = 15 22/85.

Ответ: 15 22/85.

3/8 + х = 21 2/5 - 12 2/5;

3/8 + х = 9;

х = 9 - 3/8;

х = 8 5/8.

Ответ: 8 5/8.