document.write( "Question 622962: Not sure if i did this right mind helping me out?
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document.write( "Solve the system of equations
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document.write( "{x+y+z=-3
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document.write( "{x-y+3z=-13
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document.write( "{4x+4y+4z=-15\r
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document.write( "My answer looks like this
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document.write( "x=-2,y=3,z=-4 \n" );
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Algebra.Com's Answer #391755 by math-vortex(648) You can put this solution on YOUR website! Hi, there-- \n" ); document.write( ". \n" ); document.write( "Here is how to check your answer. If you got it right, the values you found for x, y, and z will make every equation in the system true. \n" ); document.write( ". \n" ); document.write( "Just substitute -2 for x, 3 for y, and -4 for z in each equation.\r \n" ); document.write( "\n" ); document.write( "x+y+z=-3 \n" ); document.write( "(-2)+(3)+(-4)=-3 \n" ); document.write( "-3=-3 \n" ); document.write( "Check!! \n" ); document.write( ". \n" ); document.write( "x-y+3z=-13 \n" ); document.write( "(-2)-(3)+3(-4)=-13 \n" ); document.write( "-2-3-12=-13 \n" ); document.write( "-17=-13 \n" ); document.write( "Oops...Your solution doesn't work in this equation. \n" ); document.write( ". \n" ); document.write( "x=-2,y=3,z=-4 \n" ); document.write( ". \n" ); document.write( "We can see that there is a problem with your calculations because the solution must work in every equation. \n" ); document.write( ". \n" ); document.write( "Let's start with the elimination method. Multiply every term in equation {A} by -4. \n" ); document.write( "{A} x+y+z=-3 ---------------> -4x-4y-4z=12 \n" ); document.write( "{B} x-y+3z=-13 \n" ); document.write( "{C} 4x+4y+4z=-15 -----------> 4x+4y+4z=-15 \n" ); document.write( ". \n" ); document.write( "Add equations {A} and {C} \n" ); document.write( "-4x-4y-4z=12 \n" ); document.write( "4x+4y+4z=-15 \n" ); document.write( ". \n" ); document.write( "Since the variables all cancel out (-4x+4x=0, etc.) we have \n" ); document.write( "0=-3 \n" ); document.write( ". \n" ); document.write( "This result tells us that these two equations have no points in common. In 2-D, this is analogous to parallel lines. Your system has no single point (x,y,z) solution. \n" ); document.write( ". \n" ); document.write( "Here are some pictures of what solutions to systems of equations with three variables can look like: \n" ); document.write( "http://www.mathwarehouse.com/algebra/planes/systems/three-variable-equations.php \n" ); document.write( ". \n" ); document.write( "Hope this helps! Feel free to email me if you have questions about this explanation. \n" ); document.write( ". \n" ); document.write( "Ms.Figgy \n" ); document.write( "math.in.the.vortex@gmail.com\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |