document.write( "Question 1196468: Find k so that the line through (2, -3) and (k,2) is:
\n" ); document.write( "a. parallel to 3x+4y=8
\n" ); document.write( "b. perpendicular to 2x-3y= -4\r
\n" ); document.write( "\n" ); document.write( "k=?
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Algebra.Com's Answer #829305 by math_tutor2020(3817)\"\" \"About 
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\n" ); document.write( "Part (a)\r
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\n" ); document.write( "\n" ); document.write( "Let's solve the equation for y
\n" ); document.write( "3x+4y = 8
\n" ); document.write( "4y = -3x+8
\n" ); document.write( "y = -3x/4+8/4
\n" ); document.write( "y = (-3/4)x+2\r
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\n" ); document.write( "\n" ); document.write( "This equation is in y = mx+b form
\n" ); document.write( "m = -3/4 = slope
\n" ); document.write( "b = 2 = y intercept\r
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\n" ); document.write( "\n" ); document.write( "Parallel lines have equal slopes, but different y intercepts.
\n" ); document.write( "The line through (2,-3) and (k,2) will also have a slope of -3/4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's set up the slope expression for the line through those two points
\n" ); document.write( "m = slope
\n" ); document.write( "m = rise/run
\n" ); document.write( "m = (y2-y1)/(x2-x1)
\n" ); document.write( "m = (2-(-3))/(k-2)
\n" ); document.write( "m = (2+3)/(k-2)
\n" ); document.write( "m = 5/(k-2)\r
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\n" ); document.write( "\n" ); document.write( "Set this equal to -3/4 and solve for k
\n" ); document.write( "m = 5/(k-2)
\n" ); document.write( "-3/4 = 5/(k-2)
\n" ); document.write( "-3(k-2) = 4*5
\n" ); document.write( "-3k+6 = 20
\n" ); document.write( "-3k = 20-6
\n" ); document.write( "-3k = 14
\n" ); document.write( "k = -14/3\r
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\n" ); document.write( "\n" ); document.write( "======================================================================================\r
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\n" ); document.write( "\n" ); document.write( "Part (b)\r
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\n" ); document.write( "\n" ); document.write( "Solve the given equation for y
\n" ); document.write( "2x-3y = -4
\n" ); document.write( "-3y = -2x-4
\n" ); document.write( "y = -2x/(-3)-4/(-3)
\n" ); document.write( "y = (2/3)x + 4/3
\n" ); document.write( "The slope of this equation is 2/3\r
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\n" ); document.write( "\n" ); document.write( "Flip the fraction and flip the sign to get -3/2 as the perpendicular slope.
\n" ); document.write( "The original slope 2/3 and perpendicular slope -3/2 multiply to -1.\r
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\n" ); document.write( "\n" ); document.write( "We'll plug -3/2 into the slope formula we set up in part (a) earlier.\r
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\n" ); document.write( "\n" ); document.write( "m = 5/(k-2)
\n" ); document.write( "-3/2 = 5/(k-2)
\n" ); document.write( "-3(k-2) = 2*5
\n" ); document.write( "-3k+6 = 10
\n" ); document.write( "-3k = 10-6
\n" ); document.write( "-3k = 4
\n" ); document.write( "k = -4/3
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