document.write( "Question 135991: I have another question. My professor wants us to solve these equations in four different ways and show our work. I have been able to do the simpler equations but when they have 3 or 4 variables it gets a little bit more complicated.\r
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document.write( "I need to use the elimination method, substitution method, determinant and coordinates for example if if x=0 y=-5 etc...\r
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document.write( "Here are two problems that I'm having a hard time with.\r
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document.write( "#5
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document.write( "x+y+z=6
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document.write( "2x-y+3z=9
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document.write( "-x+2y+z=6\r
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document.write( "#7
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document.write( "3x+2y+z=6
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document.write( "2x-y+4z=-4
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document.write( "x+y-2z=5\r
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document.write( "Each one has to be done in four different ways. Thanks again for all the help.\r
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document.write( "Anne\r
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document.write( "
Algebra.Com's Answer #99660 by solver91311(24713)![]() ![]() You can put this solution on YOUR website! When you say 'coordinate' method, do you mean to solve the system by graphing? I certainly hope not because there is no way to render a three-dimensional coordinate system on this site. However, I'll do one of your systems by the other three methods.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Elimination: \n" ); document.write( "Replace Eq. 2 with the sum of Eq. 2 and two times Eq. 3. \n" ); document.write( "Replace Eq. 3 with the sum of Eq. 1 and Eq. 3. \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Replace Eq. 3 with the sum of Eq. 2 and -1 times Eq. 3. \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Divide Eq 3 by 3 \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Replace Eq. 1 with the sum of Eq. 1 and -1 times Eq. 3 \n" ); document.write( "Replace Eq. 2 with the sum of Eq. 2 and -5 times Eq. 3 \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Divide Eq. 2 by 3 \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Replace Eq. 1 with the sum of Eq. 1 and -1 times Eq. 2 \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Eliminate the variables with zero coefficients \n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "======================================================== \n" ); document.write( "Substitution:\r \n" ); document.write( "\n" ); document.write( "1. \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Solve Eq. 1 for x: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute the expression for x into the other two equations \n" ); document.write( "2. \n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Distribute and collect like terms: \n" ); document.write( "2. \n" ); document.write( "\n" ); document.write( "3. \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Solve equation 2 for y: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute this expression for y into the new Eq. 3 \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Distribute, simplify, collect terms \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute this value for z into the new Eq. 2 \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute the values for y and z into the original equation 1: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "============================================================ \n" ); document.write( "Cramer's Rule\r \n" ); document.write( "\n" ); document.write( "Create and evaluate the coefficient determinant\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "D = \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you don't remember how to evaluate a determinant, here is a little cartoon that shows the process. You have to take your coefficient determinant and make a 5X3 matrix by repeating the 1st and 2nd columns first. Then follow the process shown:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Yours evaluates to: -9, so we say \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Next, replace the first column representing the coefficients on the x terms with the constant term values.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "This works out to -9 as well, so you can say \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Cramer's rule says:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As you might suspect, you replace the second column with the coefficients to get \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I'll give you the \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( " |