<PRE><B>Question 249560</B>
Coordinate-system/249560 (2009-12-14 01:17:09): Give the equation of the line that contains (-9, 8) and (-9, -7)&lt;br&gt;

This one should be fairly easy.&lt;br&gt;

We know that if the x or y component is the exact same for any 2 points on a straight line, then that line must either be a horizontal or vertical line.  There are no other possibilities.&lt;br&gt;

In this example, we can see that both points share -9 as their x components.&lt;br&gt;

Thus, the equation for this line is simply:&lt;br&gt;

x=-9 which is a vertical line that intersects the point (-9,0) on the x-axis (the line shown in blue in the drawing),&lt;br&gt;

and that will hold true for EVERY real value of y.&lt;br&gt;

{{{drawing( 300, 300, -15, 15, -15, 15,grid( 1 ),blue(line( -9, -15, -9, 15 )
))}}}&lt;br&gt;

Answer 181736 by chosenpoint(17) About Me  on 2009-12-14 01:26:49&lt;br&gt;</PRE>