“ñ€’è—
2æ‚Ìê‡ ia{bj^2a^2{2aEb{b^2 3æ‚Ìê‡ ia{bj^3a^3{3a^2Eb{3aEb^2{b^3 ‚Žæ‚Ìê‡ ia{bj^nn‚b0Ea^n{n‚b1Ea^(n-1)Eb{EEE{n‚bnEb^n ‚±‚±‚ÅA‚b‚ÍA‘g‚݇‚킹(‚bombination)B