3(m^2-mn+2n^2)-2(mn-m^2+n^2)+(5mn-4n^2+1)

2025-05-21 21:43:26
推荐回答(1个)
回答(1):

原式=3m^2-3mn+6n^2-2mn+2m^2-2n^2+5mn-4n^2+1
=5m^2+1