计算:(3m-4n)(4n+3m)-(2m-n)(2m+2)?
问题描述:
计算:(3m-4n)(4n+3m)-(2m-n)(2m+2)?
答
(3m-4n)(4n+3m)-(2m-n)(2m+2)
=9m^2-16n^2-4m^2-4m+2mn+2n
=5m^2-16n^2-4m+2mn+2n计算:(4a-b^2)^2(4a-b^2)^2=16a^2-8ab^2+b^4(-m-2n)^2(-m-2n)^2=(m+2n)^2=m^2+4mn+4n^2