help me .f.2 mathss!!!!!! improtant , 20pts!!!~~

1)6ac-bd-6ad+bc
=6ac-6ad-bd+bc
=6a(c-d)+b(-d+c)
=(6a+b)(c-d)
------------------------------------------------------------------------------------------------------
2)5b² ²+6cd+3bd+10bc
=5b^4+10bc+6cd+3bd
=5b(b^3+2c)+3d(2c+b)
=無解
-------------------------------------------------------------------------------------------------------
3)2a²-9bc-6ab+3ac
=2a²-6ab-9bc+3ac
=2a(a-3b)+3c(-3b+a)
=(2a+3c)(a-3b)
-------------------------------------------------------------------------------------------------------
4)14rx-40sy+35sx+16ry
=14rx+16ry-40sy+35sx
=2r(7x+8y)+5s(-8y+7x)
=無解
-------------------------------------------------------------------------------------------------------
5)r²-rs-rt+st
=r(r-s)+t(-r+s)
=r(r-s)-t(r-s)
=(r-t)(r-s)
-------------------------------------------------------------------------------------------------------
6)mh-mk+h²-hk
=m(h-k)+h(h-k)
=(m+h)(h-k)
-------------------------------------------------------------------------------------------------------
7)6g-g²+6h-gh
=6g+6h-g²-gh
=6(g+h)+g(-g-h)
=6(g+h)-g(g+h)
=(6-g)(g+h)
-------------------------------------------------------------------------------------------------------
8)x²y+ax+bxy+ab
=x²y+bxy+ax+ab
=xy(x+b)+a(x+b)
=(xy+a)(x+b)
-------------------------------------------------------------------------------------------------------
9)y^3 +y²+y+1
=y²(y+1)+(y+1)
=(y²+1)(y+1)
-------------------------------------------------------------------------------------------------------
10)9x^3-5x²-18x+10
=9x^3-18x-5x²+10
=9x(x²-2)+5(-x²+2)
=9x(x²-2)-5(x²-2)
=(9x-5)(x²-2)
-------------------------------------------------------------------------------------------------------
11)2+3a-14a²-21a^3
=(2+3a)+7a²(2+3a)
=(1+7a²)(2+3a)
-------------------------------------------------------------------------------------------------------
12)4ab-6ab²-2+3b
=2ab(2-3b)-(2-3b)
=(2ab-1)(2-3b)
-------------------------------------------------------------------------------------------------------
13)x^3+yz+xy+x²z
=x^3+x²z+yz+xy
=x²(x+z)+y(z+x)
=(x²+y)(x+z)
-------------------------------------------------------------------------------------------------------
14)p^3+a²p+bp²+a²b
=p^3+bp²+a²p+a²b
=p²(p+b)+a²(p+b)
=(p²+a²)(p+b)
-------------------------------------------------------------------------------------------------------
15)p²r²+p²s²+q²s²+q²r²
=p²(r²+s²)+q²(s²+r²)
=(p²+q²)(r²+s²)
-------------------------------------------------------------------------------------------------------
16)b+a^3-a+ba²
=b+ba²+a^3-a
=b(1+a²)+a(a²-1)
=無解
-------------------------------------------------------------------------------------------------------
2r(7x+8y)+5s(-8y+7x)並不是因式所以上面(KR9497)第4題錯了。

2006-11-22 20:42:08 補充：
a²(a b) -a b並不是因式所以上面(KR9497)第16題錯了。

2006-11-22 20:44:23 補充：
上面(KR9497)第2題條式都寫錯,5b既2次方既2次方 6cd 3bd 10bc,他寫了5b既2次方 6cd 3bd 10bc

2006-11-22 20:48:39 補充：
請你檢查一下第2、4和16題條式有無打錯,這3條式不能進行因式分解。^3=3次方(我打唔到3次方,2次方也只是Copy)

1) 6ac-bd-6ad+bc
=6a(c-d)+b(c-d)
=(6a+b)(c-d)

2) 5b²+6cd+3bd+10bc
=5b(b+2c)+3d(b+2c)
=(5b+3d)(b+2c)

3) 2a²-9bc-6ab+3ac
=2a(a-3b)+3c(a-3b)
=(2a+3c)(a-3b)

4) 14rx+40sy-35sx+16ry
=7x(2r+5s)+8y(2r-5s)

5) r²-rs-rt+st
=r(r-s)-t(r-s)
=(r-t)(r-s)

6) mh-mk+h²-hk
=m(h-k)+h(h-k)
=(m+h)(h-k)

7) 6g-g²+6h-gh
=g(6-g)+h(6-g)
=(g+h)(6-g)

8) x²y+ax+bxy+ab
=x(xy+a)+b(xy+a)
=(x+b)(xy+a)

9) y³+y²+y+1
=y(y²+1)+(y²+1)
=(y+1)(y²+1)

10)9x³-5x²-18x+10
=9x(x²-2)-5(x²-2)
=(9x-5)(x²-2)

11)2+3a-14a²-21a³
=(2+3a)-7a²(2+3a)
=(1-7a²)(2+3a)

12)4ab-6ab²-2+3b
=2ab(2-3b)-(2-3b)
=(2ab-1)(2-3b)

13)x³+yz+xy+x²z
=x(x²+y)+z(x²+y)
=(x+z)(x²+y)

14)p³+a²p+bp²+a²b
=p(p²+a²)+b(p²+a²)
=(p+b)(p²+a²)

15)p²r²+p²s²+q²s²+q²r²
=p²(r²+s²)+q²(r²+s²)
=(p²+q²)(r²+s²)

16)b+a³-a+ba²
=a²(a+b) -a+b