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If \\[  A=\\left( \\begin{array}{ccc}
a_{11} & a_{12} & a_{13} \\\\a_{21} & a_{22} & a_{23}\\\\ a_{31} & a_{32} & a_{33}\\end{array} \\right),\\]

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\\[  C=\\left( \\begin{array}{ccc}
c_{1} \\\\ c_{2} \\\\c_{3} \\end{array} \\right),\\]

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Cramer's Rule : ${x_1}=\\frac{\\Delta_1}{\\Delta_0}$ ,  ${x_2}=\\frac{\\Delta_2}{\\Delta_0}$ , ${x_3}=\\frac{\\Delta_3}{\\Delta_0}$

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Where:\\[ \\Delta_0=\\left| \\begin{array}{ccc}
a_{11} & a_{12} & a_{13} \\\\a_{21} & a_{22} & a_{23}\\\\ a_{31} & a_{32} & a_{33}\\end{array} \\right|\\]

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\\[ \\Delta_1=\\left| \\begin{array}{ccc}
c_{1} & a_{12} & a_{13} \\\\c_{2} & a_{22} & a_{23}\\\\ c_{3} & a_{32} & a_{33}\\end{array} \\right|\\]

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\\[ \\Delta_2=\\left| \\begin{array}{ccc}
a_{11} & c_{1} & a_{13} \\\\a_{21} & c_{2} & a_{23}\\\\ a_{31} & c_{3} & a_{33}\\end{array} \\right|\\]

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\\[ \\Delta_3=\\left| \\begin{array}{ccc}
a_{11} & a_{12} & c_{1} \\\\a_{21} & a_{22} & c_{2}\\\\ a_{31} & a_{32} & c_{3}\\end{array} \\right|\\]

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What is the determinant of A=$\\var{matrixA}$? i.e $\\Delta_0$

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[[0]]

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Calculate $\\Delta_1$ [[0]]

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Hence, calculate ${x_1}$  [[1]]

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Calculate $\\Delta_2$[[0]]

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Hence, calculate ${x_2}$  [[1]]

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Calculate $\\Delta_3$[[0]]

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Hence, calculate ${x_3}$  [[1]]

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Using Cramer's rule , solve the system of equations:

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$\\var{a11}x_1+\\var{a12}x_2+\\var{a13}x_3=\\var{c1}$

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$\\var{a21}x_1+\\var{a22}x_2+\\var{a23}x_3=\\var{c2}$

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$\\var{a31}x_1+\\var{a32}x_2+\\var{a33}x_3=\\var{c3}$

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Cramers Rule applied to 3 simultaneous equations

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