document.write( "Question 374881: I am really struggling in math right now. I am working on word problems for linear systems, and Unfortunately I don't have a clue what to do, so i need some answers from you, to look them over and examine them to get a clue of what i'm trying to do.\r
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document.write( "1. Find the equation of the line that passes through the point of intersection of -2x + 4y = 14 and 5x - 3y = -14 and is perpendicular to 2x - 3y + 6 = 0.\r
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Algebra.Com's Answer #266799 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! 1. Find the equation of the line that passes through the point of intersection of -2x + 4y = 14 and 5x - 3y = -14 and is perpendicular to 2x - 3y + 6 = 0. \n" ); document.write( ": \n" ); document.write( "First of all find the point of intersection by solving the system, x & y \n" ); document.write( "-2x + 4y = 14 \n" ); document.write( "+5x - 3y = -14 \n" ); document.write( ": \n" ); document.write( "Multiply the 1st equation by 5, the 2nd equation by 2, results: \n" ); document.write( "-10x + 20y = 70 \n" ); document.write( "+10x - 6y = -28 \n" ); document.write( "------------------adding eliminates x, find y \n" ); document.write( "14y = 42 \n" ); document.write( "y = \n" ); document.write( "y = 3 \n" ); document.write( ": \n" ); document.write( "Find x using the 2nd equation: +5x - 3y = -14; replace y with 3 \n" ); document.write( "5x - 3(3) = -14 \n" ); document.write( "5x - 9 = -14 \n" ); document.write( "5x = -14 + 9 \n" ); document.write( "5x = -5 \n" ); document.write( "x = -1 \n" ); document.write( ": \n" ); document.write( "The point of intersection: x=-1, y=3 \n" ); document.write( ": \n" ); document.write( "We want the equation of a line that is perpendicular to 2x - 3y + 6 = 0 \n" ); document.write( "and pass thru the point x=-1, y=3 \n" ); document.write( ": \n" ); document.write( "Find the slope of the equation 2x - 3y + 6 = 0, put it in the slope/intercept form, namely: y = mx + b \n" ); document.write( "2x - 3y + 6 = 0 \n" ); document.write( "subtract 2x and 6 from both sides \n" ); document.write( "-3y = -2x - 6 \n" ); document.write( "Y has to be positive, mult by -1 \n" ); document.write( "3y = 2x + 6 \n" ); document.write( "Divide both sides by 3 \n" ); document.write( "y = \n" ); document.write( "The slope: m1 = \n" ); document.write( ": \n" ); document.write( "The relationship of the slopes of perpendicular lines is m1*m2 = -1 \n" ); document.write( "we know m1, find m2 \n" ); document.write( " \n" ); document.write( "divide both sides by 3/2 \n" ); document.write( "m2 = -1* \n" ); document.write( "m2 = \n" ); document.write( ": \n" ); document.write( "Using the point/slope form: y - y1 = m(x - x1) \n" ); document.write( "x1=-1; y1=3 (the point of intersection) \n" ); document.write( "m = \n" ); document.write( "so we have: \n" ); document.write( "y - 3 = \n" ); document.write( "y - 3 = \n" ); document.write( "y - 3 = \n" ); document.write( "add 3 to both sides \n" ); document.write( "y = \n" ); document.write( "which is \n" ); document.write( "y = \n" ); document.write( "y = \n" ); document.write( "Put in the standard form, multiply by 2 \n" ); document.write( "2y = -3x + 3 \n" ); document.write( "Add 3x to both sides \n" ); document.write( "3x + 2y = 3; is the equation of a line that passes thru the intersecting point -1,3 \n" ); document.write( "and is perpendicular to the line 2x - 3y + 6 = 0. \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |