document.write( "Question 255704: A line passes through the points (0,-1) and (2,3). What is the equation for the line? \n" ); document.write( "

Algebra.Com's Answer #187946 by EMStelley(208) $\"\"$ $\"About$

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The first step in finding the equation is to determine the slope. Remember that the slope of the line passing through (x1, y1) and (x2, y2) is:\r
\n" ); document.write( "\n" ); document.write( " $\"m+=+%28y2+-+y1%29%2F%28x2+-+x1%29\"$ \r
\n" ); document.write( "\n" ); document.write( "So in our case we have:\r
\n" ); document.write( "\n" ); document.write( " $\"m+=+%283+-+%28-1%29%29%2F%282+-+0%29+=+4%2F2+=+2\"$ \r
\n" ); document.write( "\n" ); document.write( "So our slope is m=2. Now, the equation for a line using the slope and one point is:\r
\n" ); document.write( "\n" ); document.write( "y - y1 = m(x - x1)\r
\n" ); document.write( "\n" ); document.write( "So using m=2 and (0, -1) we have\r
\n" ); document.write( "\n" ); document.write( "y - (-1) = 2(x - 0)\r
\n" ); document.write( "\n" ); document.write( "y + 1 = 2x\r
\n" ); document.write( "\n" ); document.write( "y = 2x-1 \n" ); document.write( "

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