\[\boxed{\text{1196\ (1196).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ 9mx - 6nx + 6my - 4ny =\]
\[= 3x \cdot (3m - 2n) + 2y \cdot (3m - 2n) =\]
\[= (3m - 2n)(3x + 2y)\]
\[2)\ 36x^{2} - 24x + 4 - y^{2} =\]
\[= (6x - 2)^{2} - y^{2} =\]
\[= (6x - 2 - y)(6x - 2 + y)\]
\[3)\ x^{2} - 4x + y^{2} + 2y + 5 =\]
\[= \left( x^{2} - 4x + 4 \right) + \left( y^{2} + 2y + 1 \right) =\]
\[= (x - 2)^{2} + (y + 1)^{2} -\]
\[не\ разложить.\]
\[4)\ 4a + 3 + a^{2} + 2b - b^{2} =\]
\[= \left( a^{2} + 4a + 4 \right) - \left( b^{2} - 2b + 1 \right) =\]
\[= (a + 2)^{2} - (b - 1)^{2} =\]
\[= (a + 2 - b + 1)(a + 2 + b - 1) =\]
\[= (a - b + 3)(a + b + 1)\ \]