Answer :

m = 3,-2, as

4m - 2 = 10                                 and                             4m - 2 = -10

4m = 12                                      and                              4m = -8

m = 3                                          and                              m = -2

dln
[tex] \left \{ {{4m-2=10} \atop {4m-2=-10}} \right. \\ \left \{ {{4m=12} \atop {4m=-8}} \right. \\ \left \{ {{m= \frac{12}{4} } \atop {m=- \frac{8}{4} }} \right. \\ \left \{ {{m=3} \atop {m=-2}} \right. [/tex]