I believe that it should be 2.
+4 means it is shifted 4 units to the left from the y axis. And -2 means it shifts 2 units to the right from the y axis. So the shift of four would leave it at -4 for the x axis and the shift of four would leave you at positive 2 for the x axis. The difference of -4 and two is six, proving that your answer is 2.
Sorry if this is wrong or doesn’t make sense.