document.write( "Question 121110: SUBSTITUTION AND ELIMINATION
\n" ); document.write( "1. 2X+Y-3Z=0
\n" ); document.write( "2. -2X+2Y+Z=-7
\n" ); document.write( "3. X-4Y-3Z=7\r
\n" ); document.write( "\n" ); document.write( "TRYING TO SOLVE FOR X,Y,Z
\n" ); document.write( " TRIED ELIMINATING X BY ADDING 1&2 WHICH GAVE ME 3Y-2Z=-7 ANS. IS NOW NEW ANS.4 THEN TRIED TO SOLVE BY ELIMINATING X AGAIN BY USING1&3 WHICH CHANGED NO.3 AFTER MULT. -2(X-4Y-3Z=7 WHICH GAVE ME -2X+4Y+6Z=-14 WHICH IN TURN GAVE ME NEW ANS.5 NOW- THIS IS WHERE I GET CONFUSED DO I SOLVE FOR EITHER Y OR Z IN NEW ANSWERS 4&5 BY FINDING NEW COMMON FACTOR, THEN SOLVING? OR DO I PLACE ANY OF THE ANSWERS INTO ANOTHER PROBLEM? \n" ); document.write( "

Algebra.Com's Answer #88873 by MathLover1(20850) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+2x+%2B+y+-+3z+=+0\"$ ЕЕЕЕЕЕ.(1)Е.=> $\"y=+-+2x+%2B+3z\"$ ЕЕЕ (I)
\n" ); document.write( "
\n" ); document.write( " $\"-2x+%2B+2y+%2B+z++=+-7\"$ ЕЕЕЕЕ..(2)Е.=> $\"z+=2x+-+2y+-7\"$ ЕЕЕЕЕ(II)\r
\n" ); document.write( "\n" ); document.write( " $\"+x+-+4y+-+3z++=+7\"$ ЕЕЕЕЕЕ..(3)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From (I) and (II) we have:\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+-2x+%2B+3z\"$ ЕЕ.(I)ЕЕЕ.substitute $\"z\"$ from (II)\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+-2x+%2B+3z\"$ ЕЕ.(
\n" ); document.write( " $\"y+=+-2x+%2B+3%282x+-+2y+-7%29\"$ ЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+-2x+%2B+6x-+6y+-21%29\"$ ЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+4x-+6y+-21%29\"$ ЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"y+%2B6y+=+4x-21%29\"$ ЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"7y+=+4x+-+21+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y+=+%284%2F7%29x+-+3\"$ ЕЕЕЕЕЕЕЕ(III)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+x+-+4y+-+3z+=+7\"$ ЕЕЕЕЕЕ..(3)ЕЕЕ..substitute $\"y\"$ from (III)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+x+-+4%28%284%2F7%29x+-+3%29+-+3z+=+7\"$ ЕЕЕЕЕЕ..substitute $\"z\"$ from (II)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+x+-+4%28%284%2F7%29x+-+3%29+-+3%282x+-+2y+-7%29+=+7\"$ ЕЕЕЕЕЕ..substitute $\"y\"$ from (III)\r
\n" ); document.write( "\n" ); document.write( " $\"+x+-+4%28%284%2F7%29x+-+3%29+-+3%282x+-+2%28%284%2F7%29x+-+3%29+-7%29+=+7\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+x+-+%28%2816%2F7%29x+-+12%29+-+%286x+-+%2824%2F7%29x+-+18%29+-21%29+=+7\"$ ЕЕЕЕЕЕ..solve for $\"x\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+x+-%2816%2F7%29x+%2B+12+-+6x+%2B+%2824%2F7%29x+-18+%2B+21+=+7\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"+-%2816%2F7%29x+-+5x+%2B+%2824%2F7%29x+%2B+15+=+7\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"++-+5x+%2B+%288%2F7%29x+%2B+15+=+7\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "\n" ); document.write( " $\"++-+5x+%2B+%288%2F7%29x+=+7+-+15\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "\n" ); document.write( " $\"++-+5x+%2B+%288%2F7%29x+=+-+8\"$ ЕЕЕЕЕЕ..multiply both sides by $\"7\"$ \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"++-+35x+%2B+8x+=+-+56\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"++-+27x+=+-+56\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"++x+=+-+56%2F-27\"$ ЕЕЕЕЕЕ..\r
\n" ); document.write( "\n" ); document.write( " $\"x+=+2.07\"$ \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"y+=+%284%2F7%29x+-+3\"$ ЕЕЕ...................(III)\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+%284%2F7%29%28+0.52%29+%96+3+\"$ ЕЕ\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+%280.57%29%28+2.07%29+-+3\"$ ЕЕ\r
\n" ); document.write( "\n" ); document.write( " $\"y+=+1.1799+-+3\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y+=+-1.8201\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y+=+-1.8\"$ \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " $\"z+=+2%282.07%29+%96+2%28-1.8%29+-7\"$ ЕЕЕЕ (II)\r
\n" ); document.write( "\n" ); document.write( " $\"z+=+4.14+%2B+3.6+-+7+\"$ ЕЕЕЕ\r
\n" ); document.write( "\n" ); document.write( " $\"z+=+7.74+-+7\"$ ЕЕЕЕ\r
\n" ); document.write( "\n" ); document.write( " $\"z+=+0.74\"$ ЕЕЕЕ\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Check:\r
\n" ); document.write( "\n" ); document.write( " $\"+2x+%2B+y+-+3z+=+0\"$ ЕЕЕЕЕЕ.(1)Е.=>\r
\n" ); document.write( "\n" ); document.write( " $\"+2%282.07%29++-1.8+%96+3+%280.74%29+=+0\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"+4.14+-+1.8+-+2.22+=+0\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"+4.14+-+4.02+=+0\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"+4+-+4+=+0\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "\n" ); document.write( " $\"+0+=+0\"$ ЕЕЕЕЕЕ.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Check second and third one tooЕЕЕЕЕЕ
\n" ); document.write( " \n" ); document.write( "

\n" );