Vector equation
A linear system written as a linear combination,
\begin{equation*} x_1 \vec{a}_1 + \cdots + x_n \vec{a}_n = \vec{b}. \end{equation*}A linear system written as a linear combination,
\begin{equation*} x_1 \vec{a}_1 + \cdots + x_n \vec{a}_n = \vec{b}. \end{equation*}