\[\boxed{\text{635\ (635).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ (3m - 2n)^{2} + 5m(4n - m) =\]
\[= 4m^{2} + 8\text{mn} + 4n^{2} =\]
\[= (2m + 2n)^{2}\]
\[2)\ (9x + 2y)^{2} - (8x + 3y)(4x - 4y) =\]
\[= 49x^{2} + 56xy + 16y^{2} =\]
\[= (7x + 4y)²\]