Explanation:
Solve the system via elimination (add the equations):
-10y + 9x = -9
+ (10y + 5x = -5)
-----------------------
14x = -14
x = -1
Plug in the value for 'x' into the second equation:
-10y + 5(-1) = -5
Solve for y:
-10y - 5 = -5
--> -10y = 0
--> y = 0
x = -1
y = 0