document.write( "Question 1014326: The three lines y=x-1, y=4-2x, y=-x-5 intersect to form a triangle. Determine the coordinates of the vertices of the triangle.
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Algebra.Com's Answer #630628 by Theo(13342)![]() ![]() You can put this solution on YOUR website! you need to solve 3 sets of 2 equations that need to be solved simultaneously. \n" ); document.write( "this will get you the 3 intersection points.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "first set is y = x-1 and y = 4-2x \n" ); document.write( "second set is y = x-1 and y = -x-5 \n" ); document.write( "third set is y = 4-2x and y = -x-5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "first set: \n" ); document.write( "start with y = x-1 and y = 4-2x \n" ); document.write( "since both x-1 and 4-2x are equal to y, you can set them equal to each other and solve for x. \n" ); document.write( "start with x-1 = 4-2x \n" ); document.write( "add 2x to both sides of the euation and add 1 to both sides of the equation to get 2x + x = 4 + 1 \n" ); document.write( "combine like terms to get 3x = 5 \n" ); document.write( "divide both sides of the equation by 3 to get x = 5/3 = 1 and 2/3 = 1.666... \n" ); document.write( "when x = 5/3, y = x-1 gets you y = 5/3 - 1 which gets you y = 2/3. \n" ); document.write( "you have x = 1.67 and y = .67. \n" ); document.write( "your intersection point is (1.67,.67) rounded to 2 decimal places.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "second set: \n" ); document.write( "start with y = x-1 and y = -x-5 \n" ); document.write( "since both x-1 and -x-5 are equal to y, you can set them equal to each other to get x-1 = -x-5 \n" ); document.write( "add x to both sides of the equation and add 1 to both sides of the equation to get x + x = -5 + 1 \n" ); document.write( "combine like terms to get 2x = -4 \n" ); document.write( "divide both sides by 2 to get x = -2 \n" ); document.write( "when x = -2, y = x-1 gets you y = -2-1 which gets you y = -3 \n" ); document.write( "you have x = -2 and y = -3. \n" ); document.write( "your intersection point is (-2,-3)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "third set: \n" ); document.write( "start with y = 4-2x and y = -x-5. \n" ); document.write( "since both 4-2x and -x-5 are equal to 6, you can set them equal to each other to get 4-2x = -x-5. \n" ); document.write( "add x to both sides of the equation and subtract 4 from both sides of the equation to get -2x + x = -5 - 4. \n" ); document.write( "combine like terms to get -x = -9 \n" ); document.write( "multiply both sides of the equation by -1 to get x = 9 \n" ); document.write( "when x = 9, y = 4-2x gets you y = 4-18 which gets you y = -14. \n" ); document.write( "you hve x = 9 and y = -14. \n" ); document.write( "your intersection point is (9,-14)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you have 3 intersection points which form your triangle. \n" ); document.write( "on the graph, the intersection points are the coordinate points.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(1.67,.67) \n" ); document.write( "(-2,-3) \n" ); document.write( "(9,-14)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i graphed the three equations and marked the intersection points. \n" ); document.write( "they agree. \n" ); document.write( "on the graph 1.67 is shown as 1.667. \n" ); document.write( "that's the same x-coordinate with different rounding applied.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "here's the graph.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |