document.write( "Question 70914: Solve the following systems by graphing.\r
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document.write( "x - 2y = 8
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document.write( "3x - 2y = 12 \n" );
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Algebra.Com's Answer #50657 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! To solve this system of equations by means of graphing you draw each graph and then \n" ); document.write( "identify the point where the two graphs cross. The x and y values at that point are the \n" ); document.write( "values of x and y that will satisfy both equations. \n" ); document.write( ". \n" ); document.write( "The two equations to graph are: \n" ); document.write( ". \n" ); document.write( "x - 2y = 8 \n" ); document.write( "3x - 2y = 12 \n" ); document.write( ". \n" ); document.write( "You can graph the equations if you can find two points for each equation. An easy way to \n" ); document.write( "to this is pick one of the equations. Set x equal to zero (making the x term disappear) \n" ); document.write( "and then solve for y. In the first (top) equation above, setting x equal to zero \n" ); document.write( "eliminates the x term and the equation becomes -2y = 8. Solve by dividing both sides \n" ); document.write( "by -2 to get y = -4. So we know that when x = 0 then y = -4. This means that the point \n" ); document.write( "(0,-4) is on the graph. Next we can do the same sort of thing only this time let \n" ); document.write( "y equal zero. The term containing y disappears and the equation reduces to x = 8. So \n" ); document.write( "the point (8, 0) is also on the graph. Plot these two points and draw a line through \n" ); document.write( "them and beyond in both directions. That completes the graph for the first equation. \n" ); document.write( ". \n" ); document.write( "Do the same sort of procedure for the second equation. Set x equal to zero, making \n" ); document.write( "the term containing x disappear and leaving the equation -2y = 12. Divide both sides \n" ); document.write( "of this equation by -2 to find that y = -6. This makes a point that is on this graph \n" ); document.write( "(0, -6). Return to the original equation and set y equal to zero. The term containing \n" ); document.write( "y disappears and you are left with 3x = 12. Divide both sides by 3 to find that x = 4. \n" ); document.write( "So we know that (4, 0) is also on this second graph. Plot the two points (0, -6) and \n" ); document.write( "(4, 0) and then draw a line through them and beyond. \n" ); document.write( ". \n" ); document.write( "If you have graphed accurately you should now see the point where the two graphs cross. \n" ); document.write( "Find the x and y values for that point and they should satisfy both of the equations. \n" ); document.write( ". \n" ); document.write( "As a check you should find that the common or crossing point for the two graphs is (2, -3). \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand graphing of linear equations for the purpose of finding \n" ); document.write( "a common solution to the set of equations. \n" ); document.write( " \n" ); document.write( " |