\[\boxed{\text{630\ (630).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[16a^{2} - 56a + 49 = (4a - 7)^{2}\]
\[9c^{2} - 12c + 4 = (3c - 2)^{2}\]
\[9x^{2} - 42\text{xy} + 49y^{2} =\]
\[= (3x - 7y)^{2}\]
\[0,01b^{2} + 2bc + 100c^{2} =\]
\[= (0,1b + 10c)^{2}\]
\[a^{2}b^{2} - 4a^{3}b^{5} + 4a^{4}b^{8} =\]
\[= \left( ab - 2a^{2}b^{4} \right)^{2}\]
\[6)\ 1,44x^{2}y^{4} - \ *y + 0,25y^{6}\]
\[1,44x^{2}y^{4} - \ 1,2xy^{4} \cdot y + 0,25y^{6} =\]
\[= \left( 1,2xy^{2} - 0,5y^{3} \right)^{2}\]
\[7)\ 64 - 80y^{20} + \ *\ y^{40}\]
\[64 - 80y^{20} + 25 \cdot y^{40} =\]
\[= (8 - 5y^{20})²\]
\[8)\ \frac{9}{25}a^{6}b² - a^{5}b^{5} + \ *\]
\[\frac{9}{25}a^{6}b^{2} - a^{5}b^{5} + \frac{25}{36}a^{4}b^{8} =\]
\[= \left( \frac{3}{5}a^{3}b - \frac{5}{6}a^{2}b^{4} \right)^{2}\]