(—2m+n—p)(2m—n—p)急求啊~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
问题描述：
(—2m+n—p)(2m—n—p)急求啊~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
如果把负号提出来怎么算,急~~~~~~~~~~~~~~~~~
答
=-(2m-n+p)(2m-n-p)
=-[(2m-n)+p][(2m-n)-p]
=-[(2m-n)²-p²]
=-(4m²-4mn+n²-p²)
=p²-4m²+4mn-n²