document.write( "Question 130091This question is from textbook algebra
\n" ); document.write( ": I thought I would understand the graphing thing, apparently I don't. Any cahnce I can get some help?\r
\n" ); document.write( "\n" ); document.write( "I have to graph
\n" ); document.write( "3x+2y=8
\n" ); document.write( "6x+4y=16\r
\n" ); document.write( "\n" ); document.write( "Please and Thank You=)
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Algebra.Com's Answer #95002 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "Start with the given system of equations:\r
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\n" ); document.write( "\n" ); document.write( "\"3x%2B2y=8\"\r
\n" ); document.write( "\n" ); document.write( "\"6x%2B4y=16\"\r
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\n" ); document.write( "\n" ); document.write( "In order to graph these equations, we need to solve for y for each equation.\r
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\n" ); document.write( "\n" ); document.write( "So let's solve for y on the first equation\r
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\n" ); document.write( "\n" ); document.write( "\"3x%2B2y=8\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"2y=8-3x\" Subtract \"3+x\" from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"2y=-3x%2B8\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3x%2B8%29%2F%282%29\" Divide both sides by \"2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3%2F2%29x%2B%288%29%2F%282%29\" Break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3%2F2%29x%2B4\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "Now lets graph \"y=%28-3%2F2%29x%2B4\" \r
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\n" ); document.write( "\n" ); document.write( "Looking at \"y=-%283%2F2%29x%2B4\" we can see that the equation is in slope-intercept form \"y=mx%2Bb\" where the slope is \"m=-3%2F2\" and the y-intercept is \"b=4\" \r
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\n" ); document.write( "\n" ); document.write( "Since \"b=4\" this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis\r
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\n" ); document.write( "\n" ); document.write( "So we have one point \r
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\n" ); document.write( "\n" ); document.write( "Now since the slope is comprised of the \"rise\" over the \"run\" this means\r
\n" ); document.write( "\n" ); document.write( "\"slope=rise%2Frun\"\r
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\n" ); document.write( "\n" ); document.write( "Also, because the slope is \"-3%2F2\", this means:\r
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\n" ); document.write( "\n" ); document.write( "\"rise%2Frun=-3%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "which shows us that the rise is -3 and the run is 2. This means that to go from point to point, we can go down 3 and over 2\r
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\n" ); document.write( "\n" ); document.write( "So starting at , go down 3 units \r
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\n" ); document.write( "\n" ); document.write( "and to the right 2 units to get to the next point \r
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\n" ); document.write( "\n" ); document.write( "Now draw a line through these points to graph \"y=-%283%2F2%29x%2B4\"\r
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\n" ); document.write( "\n" ); document.write( " So this is the graph of \"y=-%283%2F2%29x%2B4\" through the points and \r
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\n" ); document.write( "\n" ); document.write( "So let's solve for y on the second equation\r
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\n" ); document.write( "\n" ); document.write( "\"6x%2B4y=16\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"4y=16-6x\" Subtract \"6+x\" from both sides\r
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\n" ); document.write( "\n" ); document.write( "\"4y=-6x%2B16\" Rearrange the equation\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-6x%2B16%29%2F%284%29\" Divide both sides by \"4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-6%2F4%29x%2B%2816%29%2F%284%29\" Break up the fraction\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3%2F2%29x%2B4\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "Now lets add the graph of \"y=%28-3%2F2%29x%2B4\" to our first plot to get:\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+%28-3%2F2%29x%2B4%2C%28-3%2F2%29x%2B4%29+\" Graph of \"y=%28-3%2F2%29x%2B4\"(red) and \"y=%28-3%2F2%29x%2B4\"(green)\r
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\n" ); document.write( "\n" ); document.write( "From the graph, we can see that the two lines are identical (one lies perfectly on top of the other) and intersect at all points of both lines. So there are an infinite number of solutions and the system is dependent.
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