document.write( "Question 208208: SYSTEM OF 3 EQUATIONS WITH 3 UNKNOWNS\r
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document.write( "FIND THE SOLUTION SET FOR THE FOLLOWING SYSTEM OF EQUATIONS:\r
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document.write( " 4X -2Y -3Z = 8
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document.write( " 5X +3Y -4Z = 4
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document.write( " 6X -4Y -5Z = 12 \n" );
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Algebra.Com's Answer #157517 by pjalgeb(9)![]() ![]() ![]() You can put this solution on YOUR website! REQUIRED: Find the solution set {(x, y z)} for the system given.\r \n" ); document.write( "\n" ); document.write( "SOLUTION:\r \n" ); document.write( "\n" ); document.write( "The augmented 3x3 matrix for the above system of equations is:\r \n" ); document.write( "\n" ); document.write( " | 4 -2 -3 | 8 | \n" ); document.write( " | 5 3 -4 | 4 | \n" ); document.write( " | 6 -4 -5 | 12 |\r \n" ); document.write( "\n" ); document.write( "By Cramers Rule: \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "First, lets solve for D, Dx, Dy and Dz:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "D = | 4 -2 -3 | \n" ); document.write( " | 5 3 -4 | \n" ); document.write( " | 6 -4 -5 | \r \n" ); document.write( "\n" ); document.write( "D = 4(-15-16) -5(10-12) +6(8+9) \n" ); document.write( "D = 4(-31) -5(-2)+ 6(17) \n" ); document.write( "D = -124 +10 +102 \n" ); document.write( "D = -124 -112\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Dx = | 8 -2 -3 | \n" ); document.write( " | 4 3 -4 | \n" ); document.write( " | 12 -4 -5 |\r \n" ); document.write( "\n" ); document.write( "Dx = 8(-15-16) -4(10-12) + 12(8+9) \n" ); document.write( "Dx = 8(-31) -4(-2) + 12(17) \n" ); document.write( "Dx = -248 +8 + 204 \n" ); document.write( "Dx = -248 +212\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Dy = | 4 8 -3 | \n" ); document.write( " | 5 4 -4 | \n" ); document.write( " | 6 12 -5 | \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Dy = 4(-20+48) -5(-40+36) +6(-32+12) \n" ); document.write( "Dy = 4(28) -5(-4) +6(-20) \n" ); document.write( "Dy = 112 +20 -120 \n" ); document.write( "Dy = 132 -120\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Dz = | 4 -2 8 | \n" ); document.write( " | 5 3 4 | \n" ); document.write( " | 6 -4 12 |\r \n" ); document.write( "\n" ); document.write( "Dz = 4(36+16) -5(-24+32) +6(-8-24) \n" ); document.write( "Dz = 4(52) -5(8) +6(-32) \n" ); document.write( "Dz = 208 -40 -192 \n" ); document.write( "Dz = 168 -192\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: The solution set is {(3,-1,2)} \n" ); document.write( " |