化简并求职：5a^2b-[2a^2b-3(2abc-ac62）-5ac^2]-4abc,其中a=-3,b=4,c=-1

题目

化简并求职：5a^2b-[2a^2b-3(2abc-ac62）-5ac^2]-4abc,其中a=-3,b=4,c=-1

答案

5a^2b-[2a^2b-3(2abc-ac62）-5ac^2]-4abc
=5a^2b-2a^2b+6abc-3ac^2-5ac^2
=3a^2b+6abc-8ac^2
=3*9*4+6*-3*4*-1+8*3*1
=108+72+24
=224