\[50x² - 160x + 128 = 0\]
\[2 \cdot \left( 25x^{2} - 80x + 64 \right) = 0\]
\[2 \cdot (5x - 8)^{2} = 0\]
\[50x^{2} - 160x + 128 =\]
\[= 2 \cdot (5x - 8)^{2}\]