\[\boxed{\text{210\ (210).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[1)\ m^{10}\ :m^{2} = m^{10 - 2} = m^{8}\]
\[2)\ x^{5}\ :x^{4} = x^{5 - 4} = x\]
\[3)\ y^{18}\ :y^{6} = y^{18 - 6} = y^{12}\]