\[\boxed{\text{404\ (404).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ m^{3} \cdot m^{8} = m^{3 + 8} = m^{11}\]
\[\textbf{б)}\ x^{4} \cdot x^{4} = x^{4 + 4} = x^{8}\]
\[\textbf{в)}\ c^{7} \cdot c^{12} = c^{7 + 12} = c^{19}\]
\[\textbf{г)}\ p^{3} \cdot p^{11} = p^{3 + 11} = p^{14}\]
\[\textbf{д)}\ a \cdot a^{3} = a^{1 + 3} = a^{4}\]
\[\textbf{е)}\ b^{2} \cdot b = b^{2 + 1} = b^{3}\]
\[\textbf{ж)}\ 5^{9} \cdot 5^{8} = 5^{9 + 8} = 5^{17}\ \]
\[\textbf{з)}\ 3^{3} \cdot 3^{3} = 3^{3 + 3} = 3^{6}\]