求值a(a^2b-ab+2b^2)-1/2b(2a^3-2a^2+4ab-2)-3(ab+2/3b)+1/3,其中a=1

学习时间:2026-04-07 23:52:27 阅读：5687

求值a(a^2b-ab+2b^2)-1/2b(2a^3-2a^2+4ab-2)-3(ab+2/3b)+1/3,其中a=1/3 b=-20

酷酷的乌龟

2026-04-07 23:52:27

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a(a^2b-ab+2b^2)-1/2b(2a^3-2a^2+4ab-2)-3(ab+2/3b)+1/3=ba^3-ba^2+2ab^2-ba^3+ba^2+b-2ab^2-3ab-2b+1/3=-3ab-2b+1/3=20+40+1/3=181/3