Question 95076
y+9-9=0-9 [isolate the y-term to one side of the equation]
y=-9
This is a short-hand way of writing:
y= 0x-9 which means that the slope = 0, and regardless of the x-value, y will always =-9.  The points will be  (-2, -9) (0, -9) (5, -9), etc.
The y-intercept  is (0, -9)
The graph will be a horizontal line drawn straight through y=-9 (see graph below)
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The opposite is x=-9.  This means that no matter what the y-value, x will always = -9; the slope is undefined or no slope.  The graph will be a vertical line drawn straight through x=-9 at points (-9, -1) (-9, 0) (-9, 8), etc.  The x-intercept will be (-9, 0)
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{{{ graph( 300, 200, -6, 5, -10, 10, -9) }}}