已知a^3十b^3=27,a^2b一ab^2=一6'求代数式(b^3一a^3)十(a^2b一3ab^2)一2(b^3一a^2b)的值

来源：学生作业学帮网编辑：学帮网时间：2024/05/15 20:45:17

(b^3-a^3)+(a^2b-3ab^2)-2(b^3-ab^2)
=b^3-a^3+a^2b-3ab^2-2b^3+2ab^2
=-a^3-b^3+a^2b-ab^2
=-(a^3+b^3)+(a^2b-ab^2)
=-27+(-6)
=-33

(b^3一a^3)十(a^2b一3ab^2)一2(b^3一a^2b)=-（a^3十b^3）+3（a^2b一ab^2）=-27-18=-45