若m(m-2)-(m^2-2n)=-4,则[(m^2+n^2)/2]_mn=

问题描述:

若m(m-2)-(m^2-2n)=-4,则[(m^2+n^2)/2]_mn=
若m(m-2)-(m^2-2n)=-4,则[(m^2+n^2)/2]-mn=

若m(m-2)-(m^2-2n)=-4
m^2-2m-m^2+2n=-4
m-n=2
[(m^2+n^2)/2]-mn
=(m^2-2mn+n^2)/2
=(m-n)^2/2
=2^2/2
=2