1-3題唔洗做...
4)c^4(-9c^5)
5)5^18over5^20
6)a^18除a6
7)48b^2over16b^9
8)(14c^9)除(-21c^3)
9)7^9over7^3乘7^4
10)p^7‧p^2over p^13
11)2q^8 over q^6(-q^3)
12)r^4(-7r^9)over42r^11
13)(2^4)^3
14)(3p^2)^4
15)(-q^3)^6
16)(-4r^5)^3
17)(m^3n^2)^8
18)(-mn^3)^7
19)開大括號-m^2over n^3閂大括號^3
留意第19題個負號係係over線格來咖
20)開大括號2m^4 over n^5閂大括號^2
幫幫忙,,
送10點!!!17題中3既數!!係掂先好入@@''
2011-09-25 10:00 pm
回答 (2)
2011-09-25 11:08 pm
✔ 最佳答案
4)c^4 (-9c^5)
= -9 c^(4+5)
= -9c^9
5)
5^18 / 5^20
= 5^(18 - 20)
= 5^-2
= 1/5^2
= 1/25
6)
a^18 / a^6
= a^(18-6)
= a^12
7)
48b^2 / 16b^9
= (48/16) b^(2-9)
= 3 b^-7
= 3 (1/b^7)
= 3/b^7
8)
(14c^9) ÷ (-21c^3)
= -(14/21) c^(9-3)
= -(2/3) c^6
= -2c^6 / 3
9)
(7^9 / 7^3) x 7^4
= 7^(9-3+4)
= 7^10
= 282475249
但 7^9 / (7^3 x 7^4)
= 7^(9-3-4)
= 7^2
= 49
10)
p^7‧p^2 / p^13
= p^(7+2-13)
= p^-4
= 1/p^4
11)
2q^8 / q^6(-q^3)
= -2 q^(8-6-3)
= -2 q^-1
= -2/q
12)
r^4(-7r^9) / 42r^11
= (-7/42) r^(4+9-11)
= (-1/6) r^2
= -r^2 / 6
13)
(2^4)^3
= 2^(4´3)
= 2^12
= 4096
14)
(3p^2)^4
3^4 p(2´4)
= 81p^8
15)
(-q^3)^6
= (-1)^6 q^(3´6)
= q^18
16)
(-4r^5)^3
= (-4)^3 r^(5´3)
= -64r^15
17)
(m^3 n^2)^8
= m^(3´8) n^(2´8)
= m^24 n^16
18)
(-mn^3)^7
= (-1)^7 m^7 n^(3´7)
= -m^7 n^21
19)
(-m^2 / n^3)^3
= [(-1)^3 m^(2´3)] / n^(3´3)
= -m^6 / n^9
20)
(2m^4 / n^5)^2
= 2^2 m(4´2) / n^(5´2)
= 4m^8 / n^10
參考: 賣女孩的火柴
收錄日期: 2021-04-13 18:16:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110925000051KK00404