document.write( "Question 462114: How to solve systems of linear equations such as this one.
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document.write( "4x - y = -4
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document.write( "12 - 3y = 24 \n" );
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Algebra.Com's Answer #316839 by math-vortex(648)![]() ![]() You can put this solution on YOUR website! How to solve systems of linear equations such as this one. \n" ); document.write( "4x - y = -4 \n" ); document.write( "12 - 3y = 24 \n" ); document.write( "========================== \n" ); document.write( "I wonder if you meant 12x - 3y = 24 rather than 12 - 3y = 24. \n" ); document.write( ". \n" ); document.write( "I will solve the problem you typed in. If you need more help, post a new question, or send me a message. \n" ); document.write( ". \n" ); document.write( "You have two linear equations here. On a coordinate graph, the are two straight lines which intersect a single point (x, y). We will use algebra to find the coordinates of the intersection point. \n" ); document.write( ". \n" ); document.write( "First, let's simplify the second equation: \n" ); document.write( "12 - 3y = 24 \n" ); document.write( ". \n" ); document.write( "Subtract 12 from both sides. \n" ); document.write( "-3y = 24 - 12 \n" ); document.write( "-3y = 12 \n" ); document.write( ". \n" ); document.write( "Divide both sides by -3. \n" ); document.write( "y = 12/(-3) \n" ); document.write( "y = -4 \n" ); document.write( ". \n" ); document.write( "Now we can substitute -4 for y in the first equation, and solve for x. \n" ); document.write( "4x - y = -4 \n" ); document.write( "4x - (-4) = -4 \n" ); document.write( "4x + 4 = -4 \n" ); document.write( "4x = -8 \n" ); document.write( "x = -2 \n" ); document.write( ". \n" ); document.write( "Since x = -2 and y = -4 our solution is the ordered pair (-2,-4). \n" ); document.write( ". \n" ); document.write( "We should check our work with the original equations. The ordered pair (-2,-4) will make both equations true. \n" ); document.write( ". \n" ); document.write( "4x - y = -4 \n" ); document.write( "4(-2) - (-4) = -4 \n" ); document.write( "-8 + 4 = -4 \n" ); document.write( "-4 = -4 (true!) \n" ); document.write( ". \n" ); document.write( "12 - 3y = 24 \n" ); document.write( "12 - 3(-4) = 24 \n" ); document.write( "12 - (-12) = 24 \n" ); document.write( "12 + 12 = 24 \n" ); document.write( "24 = 24 (true!) \n" ); document.write( ". \n" ); document.write( "Hope this helps! \n" ); document.write( ". \n" ); document.write( "Ms.Figgy \n" ); document.write( "math.in.the.vortex \n" ); document.write( " |