document.write( "Question 634643: solve the following system of equations
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document.write( "X – 3z = -5
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document.write( "2x- y + 2z= 16
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document.write( "7x – 3y -5z =19\r
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document.write( "can you walk me thru the steps please \n" );
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Algebra.Com's Answer #399796 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! solve the following system of equations \n" ); document.write( "X – 3z = -5 \n" ); document.write( "2x- y + 2z= 16 \n" ); document.write( "7x – 3y -5z = 19 \n" ); document.write( "There is more than one way to solve this, but this is a pretty simple one. \n" ); document.write( "A combination of substitution and elimination. \n" ); document.write( ": \n" ); document.write( "Rearrange the 1st equation to use for substitution: \n" ); document.write( "x = (3z-5) \n" ); document.write( ": \n" ); document.write( "Multiply the 2nd equation by 3, subtract from the 3rd equation \n" ); document.write( "7x – 3y - 5z = 19 \n" ); document.write( "6x - 3y + 6z = 48 \n" ); document.write( "------------------- \n" ); document.write( "x + 0 - 11z = -29 \n" ); document.write( "Replace x with (3z-5) from the 1st equation \n" ); document.write( "(3z-5) - 11z =-29 \n" ); document.write( "3z - 11z = -29 + 5 \n" ); document.write( "-8z = - 24 \n" ); document.write( "z = \n" ); document.write( "z = +3 \n" ); document.write( ": \n" ); document.write( "Back to the 1st equation, replace z with 3 \n" ); document.write( "x = 3(3) - 5 \n" ); document.write( "x = 9 - 5 \n" ); document.write( "x = 4 \n" ); document.write( ": \n" ); document.write( "Use the original 2nd equation to find y, Replace x and z \n" ); document.write( "2x - y + 2z = 16 \n" ); document.write( "2(4) - y + 2(3) = 16 \n" ); document.write( "8 - y + 6 = 16 \n" ); document.write( "-y = 16 - 8 - 6 \n" ); document.write( "-y = 2 \n" ); document.write( "Y has to be positive, multiply both sides by -1 \n" ); document.write( "y = -2 \n" ); document.write( ": \n" ); document.write( "Our Solution: x=4; y=-2; z=3 \n" ); document.write( ": \n" ); document.write( ": \n" ); document.write( "Check these in the 3rd original equation \n" ); document.write( "7x – 3y -5z = 19 \n" ); document.write( "7(4) - 3(-2) - 5(3) = \n" ); document.write( "28 + 6 - 15 = 19; confirms our solutions \n" ); document.write( " |