Ответ:
- \(4x^3y-6x^2y^2=2x^2y(2x-3y)\).
- \(5a^3-15a^2b+20ab^2=5a(a^2-3ab+4b^2)\).
- \(6mn^2-9n^3+12m^2n^2=3n^2(2m-3n+4m^2)\).
- \(-3xy^2-15x^2y-21x^2y^2=-3xy(y+5x+7xy)\).
Ответ: 1) \(2x^2y(2x-3y)\); 2) \(5a(a^2-3ab+4b^2)\); 3) \(3n^2(2m-3n+4m^2)\); 4) \(-3xy(y+5x+7xy)\).
