十條中二數學題目(急~~~~~~~~~~!十分)<續>

Sing

2009-08-28 11:19 am

Q1因式分解a(x - y) + b(x - y)
Q2因式分解x(a - b) + y(b - a)
Q3因式分解 (a - b)^3 – (a - b)^2
Q4因式分解 (2x - y)(a + b) + (y – 2x)(a + b)
Q5因式分解ax – bx + cx + cy –by + ay
Q6因式分解xy + x + y + 1
運用恒等式作因式分解,回答下列各題:
Q7 x^2 – 36
Q8 16a^2 -81b^2
Q9 (x + y)^2 – 25
Q10 (a + b)^2 – (c + d)^2
注意:入面所有x並唔係乘數既意思
仲有其他題目,會另開問題問
如果個d指數睇唔清楚,我有microsoft word全部指數都上標左既版本
網址:http://samchan212.i34u.com/MATHS_2.doc
唔該

更新1:

另外十題: http://hk.knowledge.yahoo.com/question/question?qid=7009082800276

更新2:

再另外十題: http://hk.knowledge.yahoo.com/question/question?qid=7009082800301

回答 (1)

用戶7639

2009-08-28 3:21 pm

✔ 最佳答案

Q1
a(x-y)+b(x-y)
=(x-y)(a+b)

Q2
x(a-b)+y(b-a)
=x(a-b)-y(a-b)
=(a-b)(x-y)

Q3
(a - b)3–(a-b)2
=(a-b)[(a-b)-1]
=(a-b)(a-b-1)

Q4
(2x-y)(a+b)+ (y–2x)(a+b)
=(2x-y)(a+b)-(2x-y)(a+b)
=0

Q5
ax–bx+cx+cy–by+ay
=x(a-b+c)+y(a-b+c)
=(a-b+c)(x+y)

Q6
xy + x + y + 1
=x(y+1)+(y+1)
=(y+1)(x+1)

Q7 x2–36
=x2-62
=(x-6)(x+6)

Q8
16a2-81b2
=(4a)2-(9b)2
=(4a-9b)(4a+9b)

Q9
(x + y)2–25
=(x+y)2-52
=(x+y-5)(x+y+5)

Q10 (a + b)2–(c + d)2
=[(a+b)-(c+d)] [(a+b)+(c+d)]
=(a+b-c-d)(a+b+c+d)

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