document.write( "Question 24981: I need help with a problem.We are learning to solve systems by graphing and locating the point of intersection.
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document.write( "I know how to graph each system....by the slope and y-intercept, but when it comes to drawing the graph, the point of intersection is wrong. Is there a special way to start graphing the equation - top to bottom or from bottom to top.
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document.write( "Here are 2 problems: y=3/4x-4 the slope is 3/4
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document.write( " the y-intercept is -4
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document.write( " y=-1/2x+6 slope is -1/2
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document.write( " y-intercept is 6\r
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document.write( " the point of intersection or coordinates I got was (6,1)\r
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document.write( "y=-2x+5 slope is -2/1
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document.write( " y-intercept is 5\r
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document.write( "y=x-10 slope is 1
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document.write( " y-intercept is -10
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document.write( "point of intersection or coordinate i got was (7,-3)\r
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document.write( "Can there be different coordinates or only one?\r
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document.write( "Thank you \n" );
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Algebra.Com's Answer #13387 by josmiceli(19441)![]() ![]() You can put this solution on YOUR website! the coordinates at the point of intersection must solve both equations \n" ); document.write( "because the point is ON both equations, so just make sure that is true \n" ); document.write( "(1) y = 3/4x - 4 \n" ); document.write( "(2) y = (-1/2)x + 6 \n" ); document.write( "subtract (2) from (1) \n" ); document.write( "(3) 0 = (3/4x - 4) - ((-1/2)x + 6) \n" ); document.write( "(4) 0 = (5/4)x - 10 \n" ); document.write( "(5) (5/4)x = 10 \n" ); document.write( "(6) 5x = 40 \n" ); document.write( "(7) x = 8 \n" ); document.write( "now solve for y in either equation \n" ); document.write( "(8) y = ((3/4)*8) - 4 \n" ); document.write( "(9) y = 6 - 4 \n" ); document.write( "(10) y = 2 \n" ); document.write( "that means the point (8, 2) is on both lines , thus it is the intersection \n" ); document.write( "check it with the other equation \n" ); document.write( "(11) 2 = ((-1/2) * 8) + 6 \n" ); document.write( "is this true? \n" ); document.write( "(12) 2 = -4 + 6 \n" ); document.write( "yes \n" ); document.write( "just go through this whith the other equations and you'll get the intersections \n" ); document.write( "remember that TWO lines have to intersect unless they're parallel (same slope) \n" ); document.write( "THREE lines do not necessarily have to intersect all at the same point, though \n" ); document.write( "taken in pairs, they will have intersections, though \n" ); document.write( " |