Решите систему

-3 х+7 у=29

6 х+5 у=13

-3 х+7 у=29

6 х+5 у=13

2 * (-3 х) + 2*7 у=2*29

6 х+5 у=13

-6 х+14 у=58

6 х+5 у=13

-6 х+6 х+14 у+5 у=58+13

19 у=71

у=71/19

6 х+5 * 71/19=13

6 х+355/19=13

6 х=13-355/19

6 х=19*13/19 - 355/19

6 х = 247/19-355/19

6 х=-108/19

х=-108/19 : 6

х=-108/19 * 1/6

х=-108*1/19*6

х=-108/114

х=-18*6/19*6

х=-18/19

Проверка

-3 * (-18/19) + 7 * 71/19=54/19 + 497/19 = 551/19 = 29

6 * (-18/19) + 5 * 71/19 = - 108/19 + 355/19 = 247/19=13