24條因式分解.

1. 2^2x-1=32
2^2x-1=2^5
2x-1=5
2x=6
x=3

2. 25^x+4=125
5^2(x+4)=5^3
2(x+4)=3
2x+8=3
2x=-5
x=-2.5

3. 2^3x+1=4^x+3
2^3x+1=2^2(x+3)
3x+1=2(x+3)
3x+1=2x+6
x=5

4.-xy+4x
=-x(y-4)

6.-12x^2+4x
=-4x(3x-1)

7. 25m^2-10mn
=5m(5m-2n)


ps im busy at the moment, i'll answer the following as soon as possible

2007-10-14 18:23:16 補充：
下面戈位你唔好copy我d答案好bo!!

2007-10-15 02:08:00 補充：
5.ab^2-a^2b=a(b^2 - a^2b-1)8.ac-3bc+3ad-9bd =(ac-3bc)+(3ad-9bd) =c(a-3b)+3d(a-3b) =(c+3d)(a-3b)9. 2ax-bx-2ay+by =(2ax-2ay)-(bx-by) =2a(x-y)-b(x-y) =(2a-b)(x-y)

2007-10-15 02:13:44 補充：
10.2x^2-5y+2xy-5x =(2x^2 +2xy)-(5x+5y) =2x(x+y)-5(x+y) =(2x-5)(x+y)11.x^2-x-xy+y =(x^2-x)-(xy-y) =x(x-1)-y(x-1) =(x-y)(x-1)12. x^2-81y^2 =x^2 - 9^2 y^2 =(x+9y)(x-9y)13.9x^2-64y^2 =(3x+8y)(3x-8y)

2007-10-15 02:14:31 補充：
14.36x^2-4 =(6x+2)(6x-2)15.(x-9)^2 -9 =(x-9)^2 -3^2 =(x-9+3)(x-9-3) =(x-6)(x-12)16. x^2-(y-3z)^2 =(x+y-3z)(x-y+3z)

2007-10-15 02:15:15 補充：
17.x^2-3x+2 =(x-1)(x-2)18.p^2+2p-3 =(p+3)(p-1)19. x^2-8x+7 =(x-1)(x-7)

2007-10-15 02:15:59 補充：
20. x^2-4x-5 =(x-5)(x+1)21.y^2+10y-11 =(y+11)(y-1)22. 2x^2-5x+3 =(2x^2-2x)-(3x-3) =2x(x-1)-3(x-1) =(2x-3)(x-1)23.3a^2-4a-7 =(3a^2+3a)-(7a+7) =3a(a+1)-7(a+1) =(3a-7)(a+1)24. 2x^2+9x-5 =(2x^2-x)+(10x-5) =x(2x-1)+5(2x-1) =(x+5)(2x-1)

1. 2^2x-1=32
2^2x-1=2^5
2x-1=5
2x=6
x=3

2. 25^x+4=125
5^2(x+4)=5^3
2(x+4)=3
2x+8=3
2x=-5
x=-2.5

3. 2^3x+1=4^x+3
2^3x+1=2^2(x+3)
3x+1=2(x+3)
3x+1=2x+6
x=5

4.-xy+4x
=-x(y-4)

6.-12x^2+4x
=-4x(3x-1)

7. 25m^2-10mn
=5m(5m-2n)

ok la