怎樣計算下列問題 ?

條數問乜架先?? factorize嗎?
正路計ge.. 應該係抽x, y, z 出黎
即係....
= x(a-b) - y(a-b) - z(a-b)
= (x-y-z) (a-b)

ax-bx-ay+by+az-bz
=x(a-b)-y(a-b)+z(a-b)
=(x-y+z)(a-b)



...因為佢係抽出咗(-y),所以由(-ay+by),變為-y(a-b)。
因為佢為咗最後可以抽出(a-b),所以佢係抽出咗(-y)。

I know what you mean .Is it like the following ?
ax-bx-ay+by+az-bz = a(x-y+z)+b(-x+y-z)
= a(x-y+z)+(-b)(x-y+z)
= (a+(-b))(x-y+z)
= (a-b)(x-y+z)

x(a-b)-y(a-b)+z(a-b)
=(x-y+z)(a-b)