Answer:
n = -15         and          m = -3
Step-by-step explanation:
To solve the given system of equation, we will follow the steps below:
n = 5m ----------------------------------------------------------------------------(1)
n =  ---------------------------------------------------------------------(2)
 ---------------------------------------------------------------------(2)
substitute for n= 5m in equation (2)
5m =   
 
subtract  from both-side of the equation
 from both-side of the equation
5m -   =
  =  -
 -   
 
At the right-hand side of the equation   will cancel-out leaving us with just -13
  will cancel-out leaving us with just -13
5m -   = -13
  = -13
 = -13
 = -13
 = -13
 = -13
 multiply both-side of the equation by 3
3 ×   = -13 ×  3
 = -13 ×  3
At the left-hand side of the equation 3 will cancel-out 3 leaving is with just 13m
13m = -39
Divide both-side of the equation by 13
13m/13  = -39/13
m = -3
substitute m = -3 in  equation (1)
n = 5m
n = 5 (-3)
n = -15
Therefore, n = -15         and          m = -3