1: (-1,-1) is (x, y) to see if it is a solution, you would just plug in x and y and see if the equation is true. 
-4 (-1) + 2(-1) = 2 
4 + -2 = 2 
2 = 2 CORRECT 
So... plug in x and y in the second equation to Make sure it works for that one too. 
-1 + -1 = -2 
-2 = -2 CORRECT  
So, yes. (-1,-1) is a solution to both equations.