Answer :

Lilith
[tex]| 7m + 4 | = 1\\\\ 7m + 4 = 1\ \ \ \vee \ \ \ 7m + 4 = -1\\\\ 7m = 1-4\ \ \ \vee \ \ \ 7m = -1-4\\\\ 7m = -3\ \ \ \vee \ \ \ 7m = -5\\\\ m =-\frac{3}{7}\ \ \ \vee \ \ \ m = - \frac{5}{7}[/tex]


|7m + 4| = 1
7m + 4 = 1
        -4  -4
      7m = -3
        7      7
        m = -3/7