To see how they are related, let us solve the two equations.
FIRST EQUATION
[tex]m + 5 = 72[/tex]
[tex] \rightarrow \: m = 72 - 5[/tex]
[tex] \rightarrow \: m = 67[/tex]
SECOND EQUATION
[tex]m + 72 = 5[/tex]
[tex] \rightarrow \: m = 5 - 72[/tex]
[tex] \rightarrow \: m = - 67[/tex]
Hence the solutions to the two equations are ADDITIVE INVERSE of each other.
