document.write( "Question 272861: how do you solve
\n" ); document.write( "10x+2y+1z=885
\n" ); document.write( "5x+4y+1z=865
\n" ); document.write( "9x+6y+6z=1410
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Algebra.Com's Answer #199423 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'm going to solve this system by using Cramer's Rule.\r
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Solved by pluggable solver: Using Cramer's Rule to Solve Systems with 3 variables

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\n" ); document.write( " First let \"A=%28matrix%283%2C3%2C10%2C2%2C1%2C5%2C4%2C1%2C9%2C6%2C6%29%29\". This is the matrix formed by the coefficients of the given system of equations.
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\n" ); document.write( " Take note that the right hand values of the system are \"885\", \"865\", and \"1410\" and they are highlighted here:
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\n" ); document.write( " These values are important as they will be used to replace the columns of the matrix A.
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\n" ); document.write( " Now let's calculate the the determinant of the matrix A to get \"abs%28A%29=132\". To save space, I'm not showing the calculations for the determinant. However, if you need help with calculating the determinant of the matrix A, check out this solver.
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\n" ); document.write( " Notation note: \"abs%28A%29\" denotes the determinant of the matrix A.
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\n" ); document.write( " Now replace the first column of A (that corresponds to the variable 'x') with the values that form the right hand side of the system of equations. We will denote this new matrix \"A%5Bx%5D\" (since we're replacing the 'x' column so to speak).
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\n" ); document.write( " Now compute the determinant of \"A%5Bx%5D\" to get \"abs%28A%5Bx%5D%29=7920\". Again, as a space saver, I didn't include the calculations of the determinant. Check out this solver to see how to find this determinant.
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\n" ); document.write( " To find the first solution, simply divide the determinant of \"A%5Bx%5D\" by the determinant of \"A\" to get: \"x=%28abs%28A%5Bx%5D%29%29%2F%28abs%28A%29%29=%287920%29%2F%28132%29=60\"
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\n" ); document.write( " So the first solution is \"x=60\"
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\n" ); document.write( " We'll follow the same basic idea to find the other two solutions. Let's reset by letting \"A=%28matrix%283%2C3%2C10%2C2%2C1%2C5%2C4%2C1%2C9%2C6%2C6%29%29\" again (this is the coefficient matrix).
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\n" ); document.write( " Now replace the second column of A (that corresponds to the variable 'y') with the values that form the right hand side of the system of equations. We will denote this new matrix \"A%5By%5D\" (since we're replacing the 'y' column in a way).
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\n" ); document.write( " Now compute the determinant of \"A%5By%5D\" to get \"abs%28A%5By%5D%29=18480\".
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\n" ); document.write( " To find the second solution, divide the determinant of \"A%5By%5D\" by the determinant of \"A\" to get: \"y=%28abs%28A%5By%5D%29%29%2F%28abs%28A%29%29=%2818480%29%2F%28132%29=140\"
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\n" ); document.write( " So the second solution is \"y=140\"
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\n" ); document.write( " Let's reset again by letting \"A=%28matrix%283%2C3%2C10%2C2%2C1%2C5%2C4%2C1%2C9%2C6%2C6%29%29\" which is the coefficient matrix.
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\n" ); document.write( " Replace the third column of A (that corresponds to the variable 'z') with the values that form the right hand side of the system of equations. We will denote this new matrix \"A%5Bz%5D\"
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\n" ); document.write( " Now compute the determinant of \"A%5Bz%5D\" to get \"abs%28A%5Bz%5D%29=660\".
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\n" ); document.write( " To find the third solution, divide the determinant of \"A%5Bz%5D\" by the determinant of \"A\" to get: \"z=%28abs%28A%5Bz%5D%29%29%2F%28abs%28A%29%29=%28660%29%2F%28132%29=5\"
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\n" ); document.write( " So the third solution is \"z=5\"
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\n" ); document.write( " Final Answer:
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\n" ); document.write( " So the three solutions are \"x=60\", \"y=140\", and \"z=5\" giving the ordered triple (60, 140, 5)
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\n" ); document.write( " Note: there is a lot of work that is hidden in finding the determinants. Take a look at this 3x3 Determinant Solver to see how to get each determinant.
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