Respuesta :

Since you are only given one function with two variables, you can't solve the problem. So, you do trial and error for all points. 

a.) 
(0,0): 0 = -2(0) => 0 = 0 (true)
(3,-8): -8 = -2(3) => -8 = -6 (false, move to the next choice)

b.)
(1,-2): -2 = -2(1) => -2 = -2  (true)
(0,0): true
(-1,1): 1 = -2(-1) => 1=2 (false)

c.)
(-2,4): 4 = -2(-2) => 4 = 4 (true)
(1,-2): true
(0,0): true

Thus, the answer is C.