(x-y)(a-b)(α-β) 和(x+y)(a+b)(α+β)怎么去掉括号啊?

问题描述:

(x-y)(a-b)(α-β) 和(x+y)(a+b)(α+β)怎么去掉括号啊?

(x-y)(a-b)(α-β)
=(ax-bx-ay+by)(α-β)
=αax-αbx-αay+αby-βax+βbx+βay-βby
(x+y)(a+b)(α+β)
=(ax+bx+ay+by)(α-β)
=αax+αbx+αay+αby-βax-βbx-βay-βby