求因式分解 求高手幫忙 !

1. 20x^2 - 15xy= 5x (4x-3y)

2. ax+ay-y-x= ax-x+ay-y

= x( a-1 ) + y ( a-1)

= (a-1)(x+y)


Please correct me if I am wrong ^_^ !

2014-08-12 19:08:18 補充：
化簡下列各代數式

a, (3ax-9x^2)/6x=

(ax-3x^2)/2x = (a-3x)/2


b, (4x/3y)/(8xy/9x^2y^3)=

= (4x/3y)(9x^2y^3/8xy)= 36x^3y^3 / 24xy^2

=(3x^2 y) /2


c,(p+q/4p)-(2p-3q/3q)

p+q/4p -2p +1 = 1-p + q/4p

2014-08-12 19:08:34 補充：
因式分解
a. 2a^2b-4ab+8b

= 2( a^2 b -2ab +4b)

= 2b( a^2-2a +4)


b, xy(x+3y)+x(1-y)-x

= x( xy+3y^2 +1 -y -1)

= x ( xy+3y^2 -y )

= xy( x+3y-1)


c. p^3-2p^2+pq-2q

= p^2(p-2) + q (p-2)

= (p-2) (p^2+q)

4. 8zx+12yz-16xyz-24zy^2

= 4z(2x+3y) - 8yz( 2x+3y)

= (2x+3y) (4z-8yz)

= 4z (2x+3y)(1-2y)

1.
20x^2 - 15xy
=5x(4x-3y)

2.
ax+ay-y-x
=a(x+y)-(x+y)
=(x+y)(a-1)