Resum Sistemes d’Equacions (Batxillerat)

\begin{cases} a_{11} x_1 + a_{12} x_2 + ... + a_{1n} x_n = b_1 \\ a_{21} x_1 + a_{22} x_2 + ... + a_{2n} x_n = b_2 \\ ... \\ a_{m1} x_1 + a_{m2} x_2 + ... + a_{mn} x_n = b_m \end{cases}