a, ( x , y ) = { ( -4 ; -2 ) ; ( 0 ; -6 ) ; ( 2 ; 4 ) ; ( 6 ; 0 ) }
b, ( x,y ) = { ( -4 , -2 ) , ( -3 , -6 ) , ( 0 , -6 ) , ( 2, 4 ) , ( -1 , 0 ) , ( -5 , 4 ) , ( 1,2 ) }
c, ( x,y ) = { ( -5 , 0 ) , ( -3 , -2 ) , ( -1 , 4 ) , ( 1 , 2 ) }
d,
x = 4 ; y = -1
x = 2 , y = -1
e, ( x,y ) = { ( -1 , -2 ) , ( 2 , 1 ) }
g,
x = 7 , y= -2