Using our congruence statement [tex]ABCD \cong LMNO[/tex], we know that corresponding angles match, so that means that [tex]\angle M \cong \angle B[/tex]. We know that [tex]m \angle B=131[/tex], so that means that [tex]m \angle M=131[/tex]. This gives us the equation
m + 45 = 131
Subtract 45 from both sides to cancel it and we have
m = 86.