题目

5a+{3b+[6c-2a-(a-c)]}减[9a-(4b+c)] 27*｛1/9-1/9[1/3-1/3(x^3-x^2-2)]}
5a+{3b+[6c-2a-(a-c)]}-[9a-(4b+c)] 27*｛1/9-1/9[1/3-1/3(x^3-x^2-2)]}

提问时间：2021-05-05

答案

5a+{3b+[6c-2a-(a-c)]}-[9a-(4b+c)]
=5a+3b+6c-2a-a+c-9a+4b+c
=-7a+7b+8c
27*｛1/9-1/9[1/3-1/3(x^3-x^2-2)]}
=3-3*[1/3-1/3(x³-x²-2)]
=3-1+x³-x²-2
=x³-x²