\[\boxed{\text{896.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ 2abc² - 3ab^{2}c + 4a^{2}bc = abc(2c - 3b + 4a)\]
\[\textbf{б)}\ 12a²xy³ - 6axy^{5} = 6axy³(2a - y^{2})\]
\[\textbf{в)} - 15am^{3}n^{4} - 20am^{4}n^{6} = - 5am^{3}n^{4}(3 + 4mn^{2})\]
\[\textbf{г)} - 28b^{4}c^{5}y + 16b^{5}c^{6}y^{8} = 4b^{4}c^{5}y(4bcy^{3} - 7)\]