Ответ:\(12ab+18a=6a(2b+3)\);\(5x^2y-20xy^2=5xy(x-4y)\);\(4bc-10b^3c^3+8b^2c^2=2bc(2-5b^2c^2+4bc)\).Ответ: \(6a(2b+3);\ 5xy(x-4y);\ 2bc(2-5b^2c^2+4bc)\).