16.b^2-49
17.81-c^2
18.100-d^2
19.h^2-16k^2
20.m^2-36n^2
21.9p^2-64q^2
10分6題題數(因式分解)
2010-09-17 7:34 am
回答 (3)
2010-09-17 7:43 am
✔ 最佳答案
16.b^2-49= (b+7)(b-7)
17.81-c^2
= (9+c)(9-c)
18.100-d^2
= (10+d)(10-d)
19.h^2-16k^2
=(h+4k)(h-4k)
20.m^2-36n^2
=(m-6n)(m+6n)
21.9p^2-64q^2
= (3p+8q)(3p-8q)
2010-09-18 01:24:29 補充：
以上各題都係用緊平方差條式...
x^2 - y^2 = (x+y)(x-y)
呢條式係中學數學好多時會用到...
一定要記實
2010-09-17 11:07 pm
Remember : a^2 - b^2 = ( a + b ) ( a - b )
2010-09-17 8:01 am
b^2-49
=(b+7)(b-7)
81-c^2
=(9+c)(9-c)
100-d^2
=(10+d)(10-d)
h^2-16k^2
=(h+4k)(h-4k)
m^2-36n^2
=(m+6n)(m-6n)
9p^2-64q^2
=(3p+8q)(3p-8q)
=(b+7)(b-7)
81-c^2
=(9+c)(9-c)
100-d^2
=(10+d)(10-d)
h^2-16k^2
=(h+4k)(h-4k)
m^2-36n^2
=(m+6n)(m-6n)
9p^2-64q^2
=(3p+8q)(3p-8q)
參考: me
收錄日期: 2021-04-23 22:49:11
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100916000051KK01518