\[\boxed{\text{659\ (659).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ 14x + 21y = 7 \cdot (2x + 3y)\]
\[\textbf{б)}\ 15a + 10b = 5 \cdot (3a + 2b)\]
\[\textbf{в)}\ 8ab - 6ac = 2a(4b - 3c)\]
\[\textbf{г)}\ 9xa + 9xb = 9x(a + b)\]
\[\textbf{д)}\ 6ab - 3a = 3a(2b - 1)\]
\[\textbf{е)}\ 4x - 12x^{2} = 4x(1 - 3x)\]
\[\textbf{ж)}\ m^{4} - m^{2} = m^{2}(m^{2} - 1)\]
\[\textbf{з)}\ c^{3} + c^{4} = c^{3}(1 + c)\]
\[\textbf{и)}\ 7x - 14x^{3} = 7x(1 - 2x^{2})\]
\[к)\ 16y^{3} + 12y^{2} = 4y^{2}(4y + 3)\]
\[л)\ 18ab^{3} - 9b^{4} = 9b^{3}(2a - b)\]
\[м)\ 4x^{3}y^{2} - 6x^{2}y^{3} =\]
\[= 2x^{2}y^{2}(2x - 3y)\]