[tex]19 - (x + \frac{7}{12} ) = 4 \frac{9}{12} \\ x + \frac{7}{12} = 19 - 4 \frac{9}{12} \\ x + \frac{7}{12} = 18 \frac{12}{12} - 4 \frac{9}{12} \\ x + \frac{7}{12} = 14 \frac{3}{12} \\ x = 14 \frac{3}{12} - \frac{7}{12} \\ x = 13 \frac{15}{12} - \frac{7}{12} \\ x = 13 \frac{8}{12} \\ x = 13 \frac{2}{3} [/tex]

1)  19 - ( х + 7/12 ) = 4 9/12.

    х + 7/12 = 19 - 4 9/12.

    х + 7/12 = 18 12/12 - 4 9/12.

    х + 7/12 = 14 3/12.

    х = 14 3/12 - 7/12.

    х = 13 15/12 - 7/12.

    х = 6 8/12.

    х = 6 4/6.

    х = 6 2/3.

Ответ:  х = 6 2/3.