document.write( "Question 771298: The three points (5,3), (-2,1),and(-1,-5)are vertices of a triangle. Determine the equations which can be used to model each side of the triangle. \n" ); document.write( "
Algebra.Com's Answer #470112 by Alan3354(69443)\"\" \"About 
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The three points (5,3), (-2,1),and(-1,-5)are vertices of a triangle. Determine the equations which can be used to model each side of the triangle.
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\n" ); document.write( "Label them A(5,3), B(-2,1),and C(-1,-5)
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\n" ); document.write( "To find the line thru AB:
\n" ); document.write( "Find the slope:
\n" ); document.write( "slope m = diffy/diffx = (1-3)/(-2-5)
\n" ); document.write( "m = 2/7
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\n" ); document.write( "Use y = mx + b and either point to find b, the y-intercept
\n" ); document.write( "3 = (2/7)*5 + b
\n" ); document.write( "b = 11/7
\n" ); document.write( "--> y = (2/7)x + 11/7
\n" ); document.write( "Or 2x - 7y = -11/7
\n" ); document.write( "That line passes thru A & B
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\n" ); document.write( "Using determinants for BC
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\n" ); document.write( "|+x +y +1|
\n" ); document.write( "|-2 +1 +1| = 0
\n" ); document.write( "|-1 -5 +1|
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\n" ); document.write( "x*(1+5) - y*(-2+1) + 1*(10+1) = 0
\n" ); document.write( "6x + y = -11 passes thru B & C
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\n" ); document.write( "Use either method to find AC
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