document.write( "Question 98452: Please help me with these two problems.\r
\n" ); document.write( "\n" ); document.write( "Find an equation of the line with the given slope and through the given point.
\n" ); document.write( "1. slope=2;(3,11)\r
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\n" ); document.write( "\n" ); document.write( "Find an equation of the line through the given points.
\n" ); document.write( "1.(1,-5);(4,7)
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Algebra.Com's Answer #71622 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
1.\r
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\n" ); document.write( "\n" ); document.write( "\"Find an equation of the line with the given slope and through the given point.
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\n" ); document.write( "\n" ); document.write( "If you want to find the equation of line with a given a slope of \"2\" which goes through the point (\"3\",\"11\"), you can simply use the point-slope formula to find the equation:\r
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\n" ); document.write( "\n" ); document.write( "---Point-Slope Formula---
\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" where \"m\" is the slope, and is the given point\r
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\n" ); document.write( "\n" ); document.write( "So lets use the Point-Slope Formula to find the equation of the line\r
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\n" ); document.write( "\n" ); document.write( "\"y-11=%282%29%28x-3%29\" Plug in \"m=2\", \"x%5B1%5D=3\", and \"y%5B1%5D=11\" (these values are given)\r
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\n" ); document.write( "\n" ); document.write( "\"y-11=2x%2B%282%29%28-3%29\" Distribute \"2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-11=2x-6\" Multiply \"2\" and \"-3\" to get \"-6\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=2x-6%2B11\" Add 11 to both sides to isolate y\r
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\n" ); document.write( "\n" ); document.write( "\"y=2x%2B5\" Combine like terms \"-6\" and \"11\" to get \"5\" \r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So the equation of the line with a slope of \"2\" which goes through the point (\"3\",\"11\") is:\r
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\n" ); document.write( "\n" ); document.write( "\"y=2x%2B5\" which is now in \"y=mx%2Bb\" form where the slope is \"m=2\" and the y-intercept is \"b=5\"\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \"y=2x%2B5\" and plot the point (\"3\",\"11\"), we get (note: if you need help with graphing, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( " Graph of \"y=2x%2B5\" through the point (\"3\",\"11\")\r
\n" ); document.write( "\n" ); document.write( "and we can see that the point lies on the line. Since we know the equation has a slope of \"2\" and goes through the point (\"3\",\"11\"), this verifies our answer.\r
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\n" ); document.write( "\n" ); document.write( "\"Find an equation of the line through the given points.
\n" ); document.write( "(1,-5);(4,7)\"\r
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\n" ); document.write( "\n" ); document.write( "First lets find the slope through the points (\"1\",\"-5\") and (\"4\",\"7\")\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\" Start with the slope formula (note: is the first point (\"1\",\"-5\") and is the second point (\"4\",\"7\"))\r
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\n" ); document.write( "\n" ); document.write( "\"m=%287--5%29%2F%284-1%29\" Plug in \"y%5B2%5D=7\",\"y%5B1%5D=-5\",\"x%5B2%5D=4\",\"x%5B1%5D=1\" (these are the coordinates of given points)\r
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\n" ); document.write( "\n" ); document.write( "\"m=+12%2F3\" Subtract the terms in the numerator \"7--5\" to get \"12\". Subtract the terms in the denominator \"4-1\" to get \"3\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=4\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "So the slope is\r
\n" ); document.write( "\n" ); document.write( "\"m=4\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:\r
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\n" ); document.write( "\n" ); document.write( "------Point-Slope Formula------
\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" where \"m\" is the slope, and is one of the given points\r
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\n" ); document.write( "\n" ); document.write( "So lets use the Point-Slope Formula to find the equation of the line\r
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\n" ); document.write( "\n" ); document.write( "\"y--5=%284%29%28x-1%29\" Plug in \"m=4\", \"x%5B1%5D=1\", and \"y%5B1%5D=-5\" (these values are given)\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B5=%284%29%28x-1%29\" Rewrite \"y--5\" as \"y%2B5\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B5=4x%2B%284%29%28-1%29\" Distribute \"4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B5=4x-4\" Multiply \"4\" and \"-1\" to get \"-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=4x-4-5\" Subtract \"5\" from both sides to isolate y\r
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\n" ); document.write( "\n" ); document.write( "\"y=4x-9\" Combine like terms \"-4\" and \"-5\" to get \"-9\" \r
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\n" ); document.write( "\n" ); document.write( "So the equation of the line which goes through the points (\"1\",\"-5\") and (\"4\",\"7\") is:\"y=4x-9\"\r
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\n" ); document.write( "\n" ); document.write( "The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=4\" and the y-intercept is \"b=-9\"\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \"y=4x-9\" and plot the points (\"1\",\"-5\") and (\"4\",\"7\"), we get this: (note: if you need help with graphing, check out this
solver)\r
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\n" ); document.write( "\n" ); document.write( " Graph of \"y=4x-9\" through the points (\"1\",\"-5\") and (\"4\",\"7\")\r
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\n" ); document.write( "\n" ); document.write( "Notice how the two points lie on the line. This graphically verifies our answer.\r
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