\[\boxed{\text{627\ (627).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ b² - 2b + 1 = (b - 1)²\]
\[2)\ 4 + 4n + n² = (2 + n)²\]
\[3)\ x² - 14x + 49 = (x - 7)²\]
\[4)\ 4a² + 4ab + b² = (2a + b)²\]
\[5)\ 9x² - 24xy + 16y^{2} =\]
\[= (3x - 4y)²\]
\[6)\ a^{6} - 2a^{3} + 1 = (a^{3} - 1)²\]
\[7)\ 36a^{6} - 84a^{3}b^{5} + 49b^{10} =\]
\[= (6a^{3} - 7b^{5})²\]
\[8)\ 81x^{4}y^{8} - 36x^{2}y^{4}z^{6} + 4z^{12} =\]
\[= (9x^{2}y^{4} - 2z^{6})²\]