document.write( "Question 385761: Write the slope-intercept equation for the line that passes through (2, -7) and (4, -13). Please show all of your work \n" ); document.write( "
Algebra.Com's Answer #272868 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "First let's find the slope of the line through the points and \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Note: is the first point . So this means that \"x%5B1%5D=2\" and \"y%5B1%5D=-7\".\r
\n" ); document.write( "\n" ); document.write( "Also, is the second point . So this means that \"x%5B2%5D=4\" and \"y%5B2%5D=-13\".\r
\n" ); document.write( "
\n" ); document.write( "
\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
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"m=%28-13--7%29%2F%284-2%29\" Plug in \"y%5B2%5D=-13\", \"y%5B1%5D=-7\", \"x%5B2%5D=4\", and \"x%5B1%5D=2\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"m=%28-6%29%2F%284-2%29\" Subtract \"-7\" from \"-13\" to get \"-6\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"m=%28-6%29%2F%282%29\" Subtract \"2\" from \"4\" to get \"2\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"m=-3\" Reduce\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the slope of the line that goes through the points and is \"m=-3\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now let's use the point slope formula:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" Start with the point slope formula\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y--7=-3%28x-2%29\" Plug in \"m=-3\", \"x%5B1%5D=2\", and \"y%5B1%5D=-7\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y%2B7=-3%28x-2%29\" Rewrite \"y--7\" as \"y%2B7\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y%2B7=-3x%2B-3%28-2%29\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y%2B7=-3x%2B6\" Multiply\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-3x%2B6-7\" Subtract 7 from both sides. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y=-3x-1\" Combine like terms. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the equation that goes through the points and is \"y=-3x-1\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " Notice how the graph of \"y=-3x-1\" goes through the points and . So this visually verifies our answer.\r
\n" ); document.write( "\n" ); document.write( " Graph of \"y=-3x-1\" through the points and \r
\n" ); document.write( "\n" ); document.write( " \r
\n" ); document.write( "\n" ); document.write( "If you need more help, email me at jim_thompson5910@hotmail.com\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Also, feel free to check out my tutoring website\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Jim
\n" ); document.write( "
\n" );