document.write( "Question 168213: write the slope-intercept form of a linear equation, passing through each pair of points
\n" ); document.write( "(5,1) and (1,9) \n" ); document.write( "
Algebra.Com's Answer #123971 by Alan3354(69443)\"\" \"About 
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write the slope-intercept form of a linear equation, passing through each pair of points
\n" ); document.write( "(5,1) and (1,9)
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\n" ); document.write( "There are 2 ways to do this.
\n" ); document.write( "The long way:
\n" ); document.write( "Find the slope (m) of the line thru the 2 points
\n" ); document.write( "m = (y2-y1)/(x2-x1)
\n" ); document.write( "m = (1-9)/(5-1)
\n" ); document.write( "m = -8/4 = -2
\n" ); document.write( "Then use either point and the slope:
\n" ); document.write( "y-y1 = m*(x-x1)
\n" ); document.write( "y - 1 = -2*(x-5)
\n" ); document.write( "y-1 = -2x + 10
\n" ); document.write( "y = -2x + 11 (slope-intercept form)
\n" ); document.write( "2x + y = 11 (standard form)
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\n" ); document.write( "The easier way, using determinants:
\n" ); document.write( "|x y 1|
\n" ); document.write( "|1 9 1| = 0
\n" ); document.write( "|5 1 1|
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\n" ); document.write( "x*(9-1) -y*(1-5) + 1*(1-45) = 0
\n" ); document.write( "8x + 4y -44 = 0
\n" ); document.write( "2x + y = 11 (standard form)\r
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