Question 30064
{{{ y=-x }}} use an x/y table

  x   y
 -2   2
 -1   1
  0   0
  1  -1
  2  -2

{{{ graph( 300, 200, -5, 5, -5, 5, -x ) }}}

x and y have a 1:1 relationship but the slpoe id negative