document.write( "Question 304763: find the equation of the line containing the give pair of points
\n" ); document.write( "(-7, -4) and (-5, -1) \n" ); document.write( "

Algebra.Com's Answer #218229 by Alan3354(69443) $\"\"$ $\"About$

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Given 2 points example.
\n" ); document.write( "Find the equation of the line thru the points (2,1) and (3,5)
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\n" ); document.write( "This is a 2 step process. First find the slope of the line thru the points.
\n" ); document.write( "slope, m = diffy/diffx
\n" ); document.write( "m = (5-1)/(3-2)
\n" ); document.write( "m = 4
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\n" ); document.write( "Now use y = mx + b with either point to find b, the y-intercept.
\n" ); document.write( "y = mx + b
\n" ); document.write( "5 = 4*3 + b
\n" ); document.write( "b = -7
\n" ); document.write( "-------
\n" ); document.write( "y = mx + b
\n" ); document.write( "y = 4x - 7 is the answer.
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\n" ); document.write( "Another approach using determinants:
\n" ); document.write( "|x y 1|
\n" ); document.write( "|2 1 1| = 0
\n" ); document.write( "|3 5 1|
\n" ); document.write( "--------
\n" ); document.write( "x(1-5) - y(2-3) + 1(10-3) = 0
\n" ); document.write( "-4x + y + 7 = 0
\n" ); document.write( "y = 4x - 7
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\n" ); document.write( "For further assistance, or to check your work, email me via the thank you note
\n" ); document.write( " or at Moral Loophole@aol.com
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