document.write( "Question 111431: Graph x + y = –2. \n" ); document.write( "
Algebra.Com's Answer #81261 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: Graphing Linear Equations

\n" ); document.write( "
\n" ); document.write( " \"1%2Ax%2B1%2Ay=-2\"Start with the given equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"1%2Ay=-2-1%2Ax\" Subtract \"1%2Ax\" from both sides
\n" ); document.write( "
\n" ); document.write( " \"y=%281%29%28-2-1%2Ax%29\" Multiply both sides by \"1\"
\n" ); document.write( "
\n" ); document.write( " \"y=%281%29%28-2%29-%281%29%281%29x%29\" Distribute \"1\"
\n" ); document.write( "
\n" ); document.write( " \"y=-2-%281%29x\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=-1%2Ax-2\" Rearrange the terms
\n" ); document.write( "
\n" ); document.write( " \"y=-1%2Ax-2\" Reduce any fractions
\n" ); document.write( "
\n" ); document.write( " So the equation is now in slope-intercept form (\"y=mx%2Bb\") where \"m=-1\" (the slope) and \"b=-2\" (the y-intercept)
\n" ); document.write( "
\n" ); document.write( " So to graph this equation lets plug in some points
\n" ); document.write( "
\n" ); document.write( " Plug in x=-9
\n" ); document.write( "
\n" ); document.write( " \"y=-1%2A%28-9%29-2\"
\n" ); document.write( "
\n" ); document.write( " \"y=9-2\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=7\" Add
\n" ); document.write( "
\n" ); document.write( " So here's one point (-9,7)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now lets find another point
\n" ); document.write( "
\n" ); document.write( " Plug in x=-8
\n" ); document.write( "
\n" ); document.write( " \"y=-1%2A%28-8%29-2\"
\n" ); document.write( "
\n" ); document.write( " \"y=8-2\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=6\" Add
\n" ); document.write( "
\n" ); document.write( " So here's another point (-8,6). Add this to our graph
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now draw a line through these points
\n" ); document.write( "
\n" ); document.write( " So this is the graph of \"y=-1%2Ax-2\" through the points (-9,7) and (-8,6)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So from the graph we can see that the slope is \"-1%2F1\" (which tells us that in order to go from point to point we have to start at one point and go down -1 units and to the right 1 units to get to the next point), the y-intercept is (0,\"-2\")and the x-intercept is (\"-2\",0) . So all of this information verifies our graph.
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " We could graph this equation another way. Since \"b=-2\" this tells us that the y-intercept (the point where the graph intersects with the y-axis) is (0,\"-2\").
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So we have one point (0,\"-2\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now since the slope is \"-1%2F1\", this means that in order to go from point to point we can use the slope to do so. So starting at (0,\"-2\"), we can go down 1 units
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " and to the right 1 units to get to our next point
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now draw a line through those points to graph \"y=-1%2Ax-2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So this is the graph of \"y=-1%2Ax-2\" through the points (0,-2) and (1,-3)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" );