2у²-5ху х у - - х²-4у² 2у-х х+2у

2у^2–5ху х у
+ – =
(х-2у)(х+2у) х–2у х+2у

2у^2–5ху+х(х+2у)–у(х–2у)
= =
(х–2у)(х+2у)

2у^2–5ху+х^2+2ху–ху+2у^2
= =
(х–2у)(х+2у)

х^2–4ху+2у^2
=
(х–2у)(х+2у)