若m-2n=4,则4n-2m=,(m-2n)^2-2n+m+5=
问题描述:
若m-2n=4,则4n-2m=,(m-2n)^2-2n+m+5=
答
4n-2m
=2(2n-m)
=-2(m-2n)
=-2x4
=-8
(m-2n)^2-2n+m+5
=(m-2n)^2+(m-2n)+5
=4^2+4+5
=16+4+5
=25