數 中3升4問題 +++20分+++

1.簡化,用正指數表示.
a.(２a^2)^3
=(2)^3 (a^2)^3
=8a^6//

b.(a^-2 b^3)^-1
=(a^-2)^(-1) * (b^3)^-1
=a^2/b^3//


2008-07-21 11:10:32 補充：
a.(－２a^2 b^3)(８ab^2)/(２ab^3)^2
=(-2*8)a^(2+1) *b^(3+2)/2^2 *a^2*b^(3*2)
=(-16 a^3 b^5)/(4 a^2 b^6)
=-4 a/b//

(３a^2)^3(２b^-2)^4/(６ab^2)^2
=(27 a^6)(16 b^-8)/(36 a^2 b^4)
=(432 a^6 b^-8)/(36 a^2 b^4)
=12 a^4 /b^12//

2008-07-21 11:12:40 補充：
a.２００７k^0－(２００７k)^0=
=(2007)(1)-(1)
=2006//


２^-9 x８^3÷４^-2
=8^3 *4^2 /2^9
=(2^9 * 2^4 )/2^9
=2^4
=16//

2008-07-21 11:14:57 補充：
4.將以各數化為十進制數.
a.１１０１１2
=1*2^4+1*2^3+0*2^2+1x2^1+1x2^0
=16+8+2+1
=27//

b.２BE16
=2*16^4+11*16^3+14*16^2+1*16^1+6*16^0
=131072+45056+3584+16+6
=179734//

2008-07-21 11:20:15 補充：
.３.５x１０^8+６.９x１０^11
=3.5*10^8+6.9*10^3*10^8
=10^8 (3.5+6.9*1000)
=6.9035*10^11

４^(x+1)－４^(x-1)=６０
4^(x-1)(4-1)=60
4^(x-1)=20
(x-1)log 4=log20
x=3.2//

３２０００=3.2*10000=3.2*10^4//
０．００００１８９=1.89*0.00001=1.89*10^-5//