A-maths!!!!!!!!

(1 + 6x - x^2)^3 (1 - 1/x)^10
= (1 + 18x + 105x^2 + 180x^3 -105x^4 + 18x^5 - x^6)
*(1 - 10/x + 10C2 / x^2 - 10C3 / x^3 + 10C4 / x^4 - ......)

常數項
= 1 - 180 + 105 * 10C2 - 180 * 10C3 - 105 * 10C4 - 18 * 10C5 - 10C6
= -43850

呢條唔係難,係煩,你慢慢展開都計得到