计算 2(a^3)^2*a^3+(3a^3)^3-(5a)^2*a^7
问题描述：
计算 2(a^3)^2*a^3+(3a^3)^3-(5a)^2*a^7
答
2(a^3)^2*a^3+(3a^3)^3-(5a)^2*a^7
=2a^9+27a^9-25a^9
=4a^9