document.write( "Question 83033: I need help of the following equation: x + 3y = 4 \n" ); document.write( "
Algebra.Com's Answer #59577 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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Solved by pluggable solver: Graphing Linear Equations

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\n" ); document.write( " \"1%2Ax%2B3%2Ay=4\"Start with the given equation
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\n" ); document.write( " \"3%2Ay=4-1%2Ax\" Subtract \"1%2Ax\" from both sides
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\n" ); document.write( " \"y=%281%2F3%29%284-1%2Ax%29\" Multiply both sides by \"1%2F3\"
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\n" ); document.write( " \"y=%281%2F3%29%284%29-%281%2F3%29%281%29x%29\" Distribute \"1%2F3\"
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\n" ); document.write( " \"y=4%2F3-%281%2F3%29x\" Multiply
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\n" ); document.write( " \"y=%28-1%2F3%29%2Ax%2B4%2F3\" Rearrange the terms
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\n" ); document.write( " \"y=%28-1%2F3%29%2Ax%2B4%2F3\" Reduce any fractions
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\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)
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\n" ); document.write( " So to graph this equation lets plug in some points
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\n" ); document.write( " Plug in x=-8
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\n" ); document.write( " \"y=%28-1%2F3%29%2A%28-8%29%2B4%2F3\"
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\n" ); document.write( " \"y=8%2F3%2B4%2F3\" Multiply
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\n" ); document.write( " \"y=12%2F3\" Add
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\n" ); document.write( " \"y=4\" Reduce
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\n" ); document.write( " So here's one point (-8,4)
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\n" ); document.write( " Now lets find another point
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\n" ); document.write( " Plug in x=-5
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\n" ); document.write( " \"y=%28-1%2F3%29%2A%28-5%29%2B4%2F3\"
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\n" ); document.write( " \"y=5%2F3%2B4%2F3\" Multiply
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\n" ); document.write( " \"y=9%2F3\" Add
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\n" ); document.write( " \"y=3\" Reduce
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\n" ); document.write( " So here's another point (-5,3). Add this to our graph
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\n" ); document.write( " Now draw a line through these points
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\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)
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\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.
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\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\").
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\n" ); document.write( " So we have one point (0,\"4%2F3\")
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\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
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\n" ); document.write( " and to the right 3 units to get to our next point
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\n" ); document.write( " Now draw a line through those points to graph \"y=%28-1%2F3%29%2Ax%2B4%2F3\"
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\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)
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