Bist Du sicher bei den Werten?
\(\small \left(\begin{array}{rrrr}\lambda=&1&\left(\begin{array}{rrr}3&-5&7\\1&-5&9\\-4&0&4\\\end{array}\right)&\left(\begin{array}{r}x1\\x2\\x3\\\end{array}\right) = 0\\\lambda=&2 + 3 \; i&\left(\begin{array}{rrr}2 - 3 \; i&-5&7\\1&-6 - 3 \; i&9\\-4&0&3 - 3 \; i\\\end{array}\right)&\left(\begin{array}{r}x1\\x2\\x3\\\end{array}\right) = 0\\\lambda=&2 - 3 \; i&\left(\begin{array}{rrr}2 + 3 \; i&-5&7\\1&-6 + 3 \; i&9\\-4&0&3 + 3 \; i\\\end{array}\right)&\left(\begin{array}{r}x1\\x2\\x3\\\end{array}\right) = 0\\\end{array}\right)\)
\(\small ER \, := \, \left(\begin{array}{rrr}1&\frac{3 - 3 \; i}{4}&\frac{3 + 3 \; i}{4}\\2&\frac{5 - 3 \; i}{4}&\frac{5 + 3 \; i}{4}\\1&1&1\\\end{array}\right)\)
Nachrechnen bei
https://www.geogebra.org/m/upUZg79r