Below is what is called a coordinate system with a horizontal axis traditionally called the X axis and a vertical axis which is traditionally called the Y axis. The numbers to the right of zero on the horizontal axis and above zero on the vertical are positive. Numbers to the left of zero on the horizontal axis and below zero on the vertical axis are negative.  

 

Y
7
6
5
4
3
2
1
-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 X
-1
-2
-3
  -4
-5
-6
-7

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