You haven't shared the answer choices.
Still, we could invent a function for which the above statement is true:
y = mx + b, and "if x = 4, y = -2" becomes -2 = m(4) + b. Unfortunately, we have 2 unknowns here.
If we arbirtrarily let b = 3, then y = mx + b becomes y = mx + 3. Subst. 4 for x and -2 for y, we get -2 = m(4) + 3, or -5 = 4m, or m = -5/4.
Then y = mx + b becomes y = (-5/4)x + 3. (this is just an example!!!)