Congruent because both angles are the same
        
                    
             
        
        
        
Insert x = -1 and y = 4 into the first inequality:-
4 <= -(-1) + 4 = 5  
so this fits
Its A
        
                    
             
        
        
        
Well, let's use the Euclidean algorithm:
164 = 4×37 + 16
37 = 2×16 + 5
16 = 3×5 + 1
Then working backwards,
1 = 16 - 3×5
1 = 16 - 3×(37 - 2×16) = 7×16 - 3×37
1 = 7×(164 - 4×37) - 3×37 = 7×164 - 31×37
so that x = 7 and y = -31.