✔ 最佳答案
21)
a^3 (a^4)^2
= a^3 a^(4´2)
= a^3 a^8
= a^(3+8)
= a^11
22)
(-b^3)^7 b^5
= -b^(3´7) b^5
= -b^21 b^5
= -b^(21+5)
= -b^26
23)
(-c^5)^2 / c^11
= (-1)^2 c^(5´2) / c^11
= c^10 / c^11
= c^(10-11)
= c^-1
= 1/c
24)
16d^10 / (-2d^2)^4
= 16d^10 / [(-2)^4 d^(2´4)]
= 16d^10 / (16d^8)
= d^(10-8)
= d^2
26)
(-3a^2)^0
= 1 (任何唔係 0 嘅數嘅 0 次方都係 1)
27)
a (2b^3)^0
= a ´ 1
= a
28)
c^2 (-5c / c^3)^0
= c^2 ´ 1
= c^2
29)
(-5)^-2
= 1 / (-5)^2
= 1/25
30)
(-3/2)^-3
= (-2/3)^3
= [(-1)^3 (2^3 / 3^3)]
= -8/27
31)
2p^-1 / p^-5
= 2p^[-1-(-5)]
= 2p^4
32)
q^4 (-q^-6)
= -q^[4+(-6)]
= -q^-2
= 1/q^2
33)
(3^-1 m^3)^2
3^(-1´2) m^(3´2)
= 3^-2 m^6
= (1/3^2) m^6
= (m^6) / 9
34)
(2n^-4)^-3
= 2^-3 n^[(-3)´(-4)]
= (1/2^3) n^12
= (n^12) / 8
35)
(m^-1 n^3)^-2
= m^[(-1)´(-2)] n^[3´(-2)]
= m^2 n^-6
= m^2 / n^6
36)
(-m^-2 n^-1)^-2
= (-1)^-2 m^[(-2)´(-2)] n^[(-1)´(-2)]
= m^4 n^2
37)
a^-3 (a^5 b^-2)
= a^(-3+5) b^-2
= a^2 (1/b^2)
= a^2 / b^2
38)
a^4 (-a^-2 b^-1)^2
= a^4[(-1)^2 a(-2´2) b(-1´2)]
= a^4 (a^-4 b^-2)
= a^(4-4) b^-2
= a^0 (1/b^2)
= 1/b^2
39)
a^b^-4 / (a^-2 b^-3)
a^ 甚麼?
40)
(-2a^-1)^-4 / 2a^4
{(-2)^-4 a^[(-1)´(-4)] / 2a^4
= (2^-4 a^4) / 2a^4
= 2^(-4-1) a^(4 - 4)
= 2^-5
= 1/32
2011-09-30 13:53:17 補充:
若不是 Tracy 的抄襲,我也看不到第 40 題打漏了等號和關括號。
第 40 題的第二行應是:
= {(-2)^-4 a^[(-1)x(-4)]} / 2a^4