(a+bc^2)^2-6a^2b^3(1/3a^-1b^-2c^2+1/6a^-2b^-1c^4),a=7
问题描述：
(a+bc^2)^2-6a^2b^3(1/3a^-1b^-2c^2+1/6a^-2b^-1c^4),a=7
答
(a+bc^2)^2-6a^2b^3(1/3a^-1b^-2c^2+1/6a^-2b^-1c^4),a=7
=a^2+2abc^2+b^2c^4-2abc^2-b^2c^4
=a^2
=7^2
=49