document.write( "Question 660551: What is the equation of a line that passes through (-2, -1) and (-4, -3)? \n" ); document.write( "
Algebra.Com's Answer #411256 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "First let's find the slope of the line through the points and \r
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\n" ); document.write( "\n" ); document.write( "Note: is the first point . So this means that \"x%5B1%5D=-2\" and \"y%5B1%5D=-1\".\r
\n" ); document.write( "\n" ); document.write( "Also, is the second point . So this means that \"x%5B2%5D=-4\" and \"y%5B2%5D=-3\".\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.\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28-3--1%29%2F%28-4--2%29\" Plug in \"y%5B2%5D=-3\", \"y%5B1%5D=-1\", \"x%5B2%5D=-4\", and \"x%5B1%5D=-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28-2%29%2F%28-4--2%29\" Subtract \"-1\" from \"-3\" to get \"-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28-2%29%2F%28-2%29\" Subtract \"-2\" from \"-4\" to get \"-2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=1\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "So the slope of the line that goes through the points and is \"m=1\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point slope formula:\r
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\n" ); document.write( "\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" Start with the point slope formula\r
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\n" ); document.write( "\n" ); document.write( "\"y--1=1%28x--2%29\" Plug in \"m=1\", \"x%5B1%5D=-2\", and \"y%5B1%5D=-1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y--1=1%28x%2B2%29\" Rewrite \"x--2\" as \"x%2B2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=1%28x%2B2%29\" Rewrite \"y--1\" as \"y%2B1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=1x%2B1%282%29\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=1x%2B2\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=1x%2B2-1\" Subtract 1 from both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"y=1x%2B1\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"y=x%2B1\" Simplify\r
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\n" ); document.write( "\n" ); document.write( "So the equation that goes through the points and is \"y=x%2B1\"\r
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\n" ); document.write( "\n" ); document.write( " Notice how the graph of \"y=x%2B1\" goes through the points and . So this visually verifies our answer.\r
\n" ); document.write( "\n" ); document.write( " Graph of \"y=x%2B1\" through the points and \r
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