\left[ {\begin{array}{*{20}c}
 a & b \\
 c & d \\

 \end{array} } \right] = \alpha \left[ {\begin{array}{*{20}c}
 1 & 2 \\
 1 & 1 \\

 \end{array} } \right] + \beta \left[ {\begin{array}{*{20}c}
 0 & 0 \\
 0 & 0 \\

 \end{array} } \right] = \left[ {\begin{array}{*{20}c}
 \alpha & {2\alpha } \\
 \alpha & \alpha \\

 \end{array} } \right]