###### Definition1.1.6

A linear equation in the unknowns $$x_1,x_2,\ldots,x_n$$ may be written in the form

\begin{equation*} a_1x_1 + a_2x_2 + \ldots + a_nx_n = b\text{,} \end{equation*}

where $$a_1,a_2,\ldots,a_n$$ are real numbers known as coefficients.

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