document.write( "Question 39698This question is from textbook College Algebra
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document.write( ": I can't figure out how to solve this equation
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document.write( "6x-3y=1
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document.write( "-12x+6y=-2 I need to solve using a matrix but I can't figure out how to get the answer in the back of the book. It says the answer is (3y+1/6,y) \n" );
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Algebra.Com's Answer #25142 by venugopalramana(3286)![]() ![]() You can put this solution on YOUR website! I can't figure out how to solve this equation \n" ); document.write( "6x-3y=1 \n" ); document.write( "-12x+6y=-2 I need to solve using a matrix but I can't figure out how to get the answer in the back of the book. It says the answer is (3y+1/6,y) \n" ); document.write( "THESE ARE DEPENDENT EQNS..HENCE YOU MIGHT BE FACING THE DIFFICULTY \n" ); document.write( "HOPE YOU KNOW THE METHOD \n" ); document.write( "AUGMENTED MATRIX IS \n" ); document.write( "....COEF.OF X.....COEF.OF Y.....CONSTANT......UNIT MATRIX \n" ); document.write( "............6.......-3..............1...........1..............0 \n" ); document.write( "...........-12..... .6.............-2...........0..............1 \n" ); document.write( " \n" ); document.write( "WE HAVE TO CONVERT IT NOW.. \n" ); document.write( "1.NEW R1=OLD R1/6 \n" ); document.write( "............1........-3/6...........1/6.........1/6.............0 \n" ); document.write( "............-12........6.............-2..........0..............1 \n" ); document.write( "2.NEW R2 =OLD R2+12*R1 \n" ); document.write( "............1.........-1/2...........1/6.........1/6.............0 \n" ); document.write( "............0..........0.............0............2..............1 \n" ); document.write( "NOW WE CANNOPT MAKE SECOND ROW ,SECOND COLUMN ELEMENT AS 1 ANY MORE AS IS NORMALLY DONE IN CONSISTENT AND INDEPENDENT EQN. \n" ); document.write( "THE PRESENCE OF ZEROS IN ALL 3 COLUMNS IN SECOND ROW INDICATES THAT THE EQN.GIVEN ARE DEPENDENT .SO WE HAVE ONLY ONE INDEPENDENT EQN.IN 2 UNKNOWNS .HENCE WE SHALL NOT HAVE A UNIQUE SOLUTION.WE GET AN INFINITE SET OF ANSWERS .THEY ARE GIVEN BY FIRST ROW WHICH TELLS US THAT \n" ); document.write( "1X-Y/2=1/6 \n" ); document.write( "SO TO GET ANY SET OF SOLUTION PUT X ANY VALUE AND FIND Y OR VICEVERSA. \n" ); document.write( "SUPPOSE WE PUT X=0...THEN -Y/2=1/6...OR....Y=-2/6=-1/3... \n" ); document.write( " SO SOLUTION SET IS (0,-1/3) \n" ); document.write( "OR PUT X=1/6....THEN Y=0.. \n" ); document.write( "SO SOLUTION SET IS (*1/6,0)....ETC.... \n" ); document.write( "..SAME WAY WITH Y \n" ); document.write( "PUT Y=0...THEN X=1/6.... \n" ); document.write( "SO SOLUTION SET IS (1/6,0) \n" ); document.write( "IN GENERAL IF WE TAKE Y=Y..THEN 1X=Y/2+1/6 = (3Y+1)/6 \n" ); document.write( "SO THE SOLUTION SET IS \n" ); document.write( "{(3Y+1)/6,Y}..THIS IS WHAT IS GIVEN IN YOUR BOOK. \n" ); document.write( "IT MEANS PUT ANY VALUE FOR Y IN THIS SET AND THE RESULTANT NUMBERS WILL GIVE YOU A SOLUTION FOR THE GIVEN EQNS. \n" ); document.write( "BUT YOU NEED NOT GIVE THIS ONLY AS AN ANSWER.FOR EX. YOU CAN PUT X=X AND THEN \n" ); document.write( "X-Y/2=1/6...SO....Y/2=X-1/6....OR....Y=2X-1/3=(6X-1)/3...HENCE THE ANSWER COULD ALSO BE GIVEN AS {X,(6X-1)/3}...GOT IT?BUT YOU HAVE TO GIVE A GENERAL SOLUTION LIKE THIS AND NOT JUST 1 SET OF VALUES LIKE (0,-1/3) \n" ); document.write( " |