see my answer above: (x+a)*(y-a) = xy-ax+ay-a^2 =xy+a(y-x-a)
所有跟帖:
• you are smart :) -爱家的男人- ♂ (0 bytes) () 01/22/2010 postreply 08:03:42
• Yes, when I was a little kid, thanks! -linda2- ♀ (0 bytes) () 01/22/2010 postreply 08:10:43
• you are smart :) -爱家的男人- ♂ (0 bytes) () 01/22/2010 postreply 08:03:42
• Yes, when I was a little kid, thanks! -linda2- ♀ (0 bytes) () 01/22/2010 postreply 08:10:43