document.write( "Question 957265: Solve the following system of equations by graphing and find the intersection point.
\n" ); document.write( "X+3y=4 and 2x-y=1
\n" ); document.write( "How do I get X's and Y's to plot on the graph?
\n" ); document.write( "

Algebra.Com's Answer #584900 by MathLover1(20849)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "if you have \"x%2B3y=4\"\r
\n" ); document.write( "\n" ); document.write( "to get X's and Y's to plot on the graph, you choose values for X's and calculate Y's \r
\n" ); document.write( "\n" ); document.write( "here are the steps to graph a linear function:\r
\n" ); document.write( "\n" ); document.write( "\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%2B3%2Ay=4\"Start with the given equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"3%2Ay=4-1%2Ax\" Subtract \"1%2Ax\" from both sides
\n" ); document.write( "
\n" ); document.write( " \"y=%281%2F3%29%284-1%2Ax%29\" Multiply both sides by \"1%2F3\"
\n" ); document.write( "
\n" ); document.write( " \"y=%281%2F3%29%284%29-%281%2F3%29%281%29x%29\" Distribute \"1%2F3\"
\n" ); document.write( "
\n" ); document.write( " \"y=4%2F3-%281%2F3%29x\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29%2Ax%2B4%2F3\" Rearrange the terms
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29%2Ax%2B4%2F3\" Reduce any fractions
\n" ); document.write( "
\n" ); document.write( " So the equation is now in slope-intercept form (\"y=mx%2Bb\") where \"m=-1%2F3\" (the slope) and \"b=4%2F3\" (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=-8
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29%2A%28-8%29%2B4%2F3\"
\n" ); document.write( "
\n" ); document.write( " \"y=8%2F3%2B4%2F3\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=12%2F3\" Add
\n" ); document.write( "
\n" ); document.write( " \"y=4\" Reduce
\n" ); document.write( "
\n" ); document.write( " So here's one point (-8,4)
\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=-5
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29%2A%28-5%29%2B4%2F3\"
\n" ); document.write( "
\n" ); document.write( " \"y=5%2F3%2B4%2F3\" Multiply
\n" ); document.write( "
\n" ); document.write( " \"y=9%2F3\" Add
\n" ); document.write( "
\n" ); document.write( " \"y=3\" Reduce
\n" ); document.write( "
\n" ); document.write( " So here's another point (-5,3). 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=%28-1%2F3%29%2Ax%2B4%2F3\" through the points (-8,4) and (-5,3)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So from the graph we can see that the slope is \"-1%2F3\" (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 3 units to get to the next point), the y-intercept is (0,\"1.33333333333333\") ,or (0,\"4%2F3\"), and the x-intercept is (\"4\",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=4%2F3\" this tells us that the y-intercept (the point where the graph intersects with the y-axis) is (0,\"4%2F3\").
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So we have one point (0,\"4%2F3\")
\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%2F3\", this means that in order to go from point to point we can use the slope to do so. So starting at (0,\"4%2F3\"), we can go down 1 units
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " and to the right 3 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=%28-1%2F3%29%2Ax%2B4%2F3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So this is the graph of \"y=%28-1%2F3%29%2Ax%2B4%2F3\" through the points (0,1.33333333333333) and (3,0.333333333333333)
\n" ); document.write( "

\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "steps to solve a system by graphing:\r
\n" ); document.write( "\n" ); document.write( "your system is\r
\n" ); document.write( "\n" ); document.write( "\"2x-y=1\"....eq.1
\n" ); document.write( "\"x%2B3y=4\"....eq.2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: Solve the System of Equations by Graphing

\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Start with the given system of equations:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"1x%2B3y=4\"
\n" ); document.write( "
\n" ); document.write( " \"2x-y=1\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " In order to graph these equations, we need to solve for y for each equation.
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So let's solve for y on the first equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"1x%2B3y=4\" Start with the given equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"3y=4-x\" Subtract \"+x\" from both sides
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"3y=-x%2B4\" Rearrange the equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-x%2B4%29%2F%283%29\" Divide both sides by \"3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29x%2B%284%29%2F%283%29\" Break up the fraction
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-1%2F3%29x%2B4%2F3\" Reduce
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now lets graph \"y=%28-1%2F3%29x%2B4%2F3\" (note: if you need help with graphing, check out this solver)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+%28-1%2F3%29x%2B4%2F3%29+\" Graph of \"y=%28-1%2F3%29x%2B4%2F3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So let's solve for y on the second equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"2x-y=1\" Start with the given equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"-y=1-2x\" Subtract \"2+x\" from both sides
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"-y=-2x%2B1\" Rearrange the equation
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-2x%2B1%29%2F%28-1%29\" Divide both sides by \"-1\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=%28-2%2F-1%29x%2B%281%29%2F%28-1%29\" Break up the fraction
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=2x-1\" Reduce
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now lets add the graph of \"y=2x-1\" to our first plot to get:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+%28-1%2F3%29x%2B4%2F3%2C2x-1%29+\" Graph of \"y=%28-1%2F3%29x%2B4%2F3\"(red) and \"y=2x-1\"(green)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " From the graph, we can see that the two lines intersect at the point (\"1\",\"1\") (note: you might have to adjust the window to see the intersection)
\n" ); document.write( " \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );