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.