Express the system of equations in matrix form.

Find the solution to the system of equations.

attempting to express the system in matrix form     M1

\(\left( {\begin{array}{*{20}{c}}
  {0.1}&{ - 1.7}&{0.9} \\
  { - 2.4}&{0.3}&{3.2} \\
  {2.5}&{0.6}&{ - 3.7}
\end{array}} \right)\left( {\begin{array}{*{20}{c}}
  x \\
  y \\
  z
\end{array}} \right) = \left( {\begin{array}{*{20}{c}}
  { - 4.4} \\
  {1.2} \\
  {0.8}
\end{array}} \right)\)     A1

Note: Award M1A1 for a correct augmented matrix.

[2 marks]

either direct GDC use, attempting elimination or using an inverse matrix.     (M1)

\(\left( {\begin{array}{*{20}{c}}
  x \\
  y \\
  z
\end{array}} \right) = \left( {\begin{array}{*{20}{c}}
  { - 2.4} \\
  {1.6} \\
  { - 1.6}
\end{array}} \right)\) (correct to 2sf) or \(\left( {\begin{array}{*{20}{c}}
  { - 2.40} \\
  {1.61} \\
  { - 1.57}
\end{array}} \right)\) (correct to 3sf) or \(\left( {\begin{array}{*{20}{c}}
  { - \frac{{932}}{{389}}} \\
  {\frac{{628}}{{389}}} \\
  { - \frac{{612}}{{389}}}
\end{array}} \right)\) (exact)     A2

[3 marks]

This was generally well done. In part (a), some candidates expressed the system of equations in the form \(XA = B\). In part (b), the overwhelming majority of candidates who used a direct GDC approach obtained the correct solution. Candidates who attempted matrix methods such as row reduction without a GDC were generally unsuccessful.

This was generally well done. In part (a), some candidates expressed the system of equations in the form \(XA = B\). In part (b), the overwhelming majority of candidates who used a direct GDC approach obtained the correct solution. Candidates who attempted matrix methods such as row reduction without a GDC were generally unsuccessful.