document.write( "Question 55978: I have the equations
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document.write( "3x+ y+2z=6
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document.write( " x+ y+4z=3
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document.write( "2x+3y+2z=2
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document.write( "I'm supposed to solve using elimination. I've tried eliminating every variable but the answer is never right when i check it. Please help. \n" );
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Algebra.Com's Answer #37964 by funmath(2933)![]() ![]() ![]() You can put this solution on YOUR website! Solve by elimination: \n" ); document.write( "E1) 3x+ y+2z=6 \n" ); document.write( "E2) x+ y+4z=3 \n" ); document.write( "E3) 2x+3y+2z=2 \n" ); document.write( "Eliminate the y in the E1) and E2), multiply E2) by -1 and add them together: \n" ); document.write( "-1(x+y+4z)=-1(3) \n" ); document.write( "--------------- \n" ); document.write( "3x+y+2z=6 \n" ); document.write( "-x-y-4z=-3 \n" ); document.write( "__________ \n" ); document.write( "2x+0y-2z=3 \n" ); document.write( "E4) 2x-2z=3 \n" ); document.write( "+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ \n" ); document.write( "Eliminate the y in E2) and E3), multiply E2 by -3 and add them together: \n" ); document.write( "-3(x+y+4z)=-3(3) \n" ); document.write( "--------------- \n" ); document.write( "-3x-3y-12z=-9 \n" ); document.write( "2x+3y+2z=2 \n" ); document.write( "____________ \n" ); document.write( "-x+0y-10z=-7 \n" ); document.write( "E5) -x-10z=-7 \n" ); document.write( "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ \n" ); document.write( "Eliminate the x in E4) and E5), multiply E5) by 2 and add them together: \n" ); document.write( "2(-x-10z)=2(-7) \n" ); document.write( "------------------ \n" ); document.write( "2x-2z=3 \n" ); document.write( "-2x-20z=-14 \n" ); document.write( "_____________ \n" ); document.write( "0x-22z=-11 \n" ); document.write( "-22z=-11 \n" ); document.write( " \n" ); document.write( "z=1/2 \n" ); document.write( "+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ \n" ); document.write( "Sustitute z=1/2 into E5) and solve for x: \n" ); document.write( " \n" ); document.write( "-x-5=-7 \n" ); document.write( "-x-5+5=-7+5 \n" ); document.write( "-x=-2 \n" ); document.write( "-(-x)=-(-2) \n" ); document.write( "x=2 \n" ); document.write( "+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ \n" ); document.write( "Substitute z=1/2 and x=2 into E1,E2, or E3 and solve for y. I'm going with E2. \n" ); document.write( "(2)+y+4(1/2)=3 \n" ); document.write( "2+y+2=3 \n" ); document.write( "y+4=3 \n" ); document.write( "y+4-4=3-4 \n" ); document.write( "y=-1 \n" ); document.write( "Therefore the solution is (x,y,z)=(2,-1,1/2) \n" ); document.write( "I'll leave it to you to check. If you can't do that then let me know. I checked it with a calculator. \n" ); document.write( "Happy Calculating!!! \n" ); document.write( " |