Ch (3) (x²) (-2)(x-¹)
n = 3₁ (²3.3²₁ (-8)
n
12-30
Ch
-> (₂₁ 3³ (-2)^² x
(3), 08 (4)
= -4320
2
6. 若(ax+二)(展開式中²項的係數為6,則實數a 之值為±
1
12-3n-2n
X
2
4-n
4-n
n
Q₁²₁4 = 61
4-n
-5n+12
( ₁ (a) (x²) (2)^(x^²) = 2^ 2^. X
n
1t² n = 2
Q = = = = =
□ 7. 設自然數n ≥3且已知(1-x)+(1-x)²+ + +(1-x)'的展開式中,項的係數可表為
an² + bn² + cn + d, 式中 a, b, c, d 為常數, 則下列何者為真? (B).
3
(A) a = 1, d=b+c (B) a+c=b+d (C)a= c (D) a=3, b=0 (E) a+b+c+d==
n n
(h() (-1)^x^
n=² =) ( ²₂² (-1) ² x ²
