\text (E - A) \vec x = \vec y \compose{=}{=\Rightar}\\Gau\s-Algorithmus:\\\begin{array}{ccc|c} 1 & -0,0625 & -0,2 & 57\\_{ }\\0&0,75&-0,1&26\\_{ }\\-0,3&-0,125&0,9&60\\\hline\end{array}\\\begin{array}{ccc|c} 1 & -0,0625 & -0,2 & 57\\_{ }\\0&0,75&-0,1&26\\_{ }\\0&-1,4375&8,4&771\\\hline\end{array}\\\begin{array}{ccc|c} 1 & -0,0625 & -0,2 & 57&&&\Rightar x_{\fs11} = 80\\_{ }\\0&0,75&-0,1&26&&\Rightar x_{\fs13} = 100\\_{ }\\0&61,5625&0&2955& \Rightar x_{\fs12} = 48\end{array}\\\compose{=}{=\Rightar} \vec x = \begin{pmatrix}80\\ \\48\\ \\100\end{pmatrix}