次の計算をし，ア～コに当てはまる数を半角英数字で入力しなさい。

1. \(\displaystyle 2a \times (-3a)^2 =\fbox{ア}a^{\fbox{イ}} \)
2. \(\displaystyle 18ab \times \left( -\frac{1}{3}a \right) ^2 =\fbox{ウ}a^{\fbox{エ}}b \)
3. \(\displaystyle \frac{1}{3}ab^2 \times (-3ab)^2 =\fbox{オ}a^{\fbox{カ}}b^{\fbox{キ}} \)
4. \(\displaystyle (-3a^2 b)^3 \times (-ab^2)^4 =\fbox{ク}a^{\fbox{ケ}}b^{\fbox{コ}} \)