若m-n=2,mn=1,则多项式(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值是_.

问题描述:

若m-n=2,mn=1,则多项式(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值是______.

原式=-2mn+2m+3n-3mn-2n+2m-m-4n-mn
=3(m-n)-6mn
=3×2-6×1
=0.