我要提问:  

问题
4乘(x+ 2y)的平方-25乘(x-y)的平方

答案
4乘(x+ 2y)的平方-25乘(x-y)的平方
=【2(x+2y)+5(x-y)]【2(x+2y)-5(x-y)]
=(7x-y)(9y-3x)
=3(7x-y)(3y-x)
粤ICP备05029465号 Power by: YESTIME.NET
Please change your screen resolutidn to1024×768 Total ,
Copyright © 2008-2009 中小学教育资源网(yestime.net). all Rights Reserved.