數學暑作既代數簡介及簡易指數2

2007-08-11 10:16 am
1.
解以下兩條不等式:
a.2(x+1)>4
b.7x-9>9x+7

2.
考慮數列-3,9,-27,...
寫出a.第5項
b.通項,並由此寫出第100項。

3.化簡
a.(6ab)(-7 a2次方 b2次方)
b.(-8 a4次方 b3次方)(-9 a3次方 b2次方)

4.計算
a.-8 4次方
b.
(2 6次方)5次方
----------------------
(2 7次方)4次方

回答 (3)

2007-08-31 6:43 am
1a.
2(x+1)>4
2x+2>4
2x+2-2>4-2
2x>2
2x/2>2/2
x>1

1b.
7x-9>9x+7
7x-9x-9>9x+7-9x
-2x-9+9=7+9
-2x=16
-2x/-2=16/-2
x=-8

2a. -243
2b. 通項(-3^n)並由此寫出第100項(-3^100)-5.153775207^47

3a.
(6ab)(-7 a2次方 b2次方)
= -42a3次方b3次方

3b.
(-8 a4次方 b3次方)(-9 a3次方 b2次方)
= 72a7次方b5次方

4a.
-8^4
= -8x-8x-8x-8
= +(8x8x8x8)
= 64x8x8
= 512x8
= 4096

b.
(2 6次方)5次方
----------------------
(2 7次方)4次方
= 2^6x5/2^7x4
= 2^30/2^28
= 2^30-28
= 2^2
= 4
2007-08-11 5:43 pm
1a.
2(x+1)>4
2x+2>4
2x+2-2>4-2
2x>2
2x/2>2/2
x>1

1b.
7x-9>9x+7
7x-9x-9>9x+7-9x
-2x-9+9=7+9
-2x=16
-2x/-2=16/-2
x=-8

2a. -243
2b. 通項(-3^n)並由此寫出第100項(-3^100)-5.153775207^47

3a.
(6ab)(-7 a2次方 b2次方)
= -42a3次方b3次方

3b.
(-8 a4次方 b3次方)(-9 a3次方 b2次方)
= 72a7次方b5次方

4a.
-8^4
= -8x-8x-8x-8
= +(8x8x8x8)
= 64x8x8
= 512x8
= 4096

b.
(2 6次方)5次方
----------------------
(2 7次方)4次方
= 2^6x5/2^7x4
= 2^30/2^28
= 2^30-28
= 2^2
= 4
2007-08-11 10:35 am
^<--等於次方

1A
2(x+1)>4
2x+2>4
2x>2
x>1

1B
7x-9>9x+7
-16>2x
16<2x
8


收錄日期: 2021-04-13 16:07:28
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070811000051KK00498

檢視 Wayback Machine 備份