1.8m^2-9[4mn+m^2-3(2m^2+mn)]+(-10m^2-2mn)=?2.1/4a^2b^2[3ab(a+b)-5a(ab-b^2)]
问题描述：
1.8m^2-9[4mn+m^2-3(2m^2+mn)]+(-10m^2-2mn)=?2.1/4a^2b^2[3ab(a+b)-5a(ab-b^2)]
答
1. 8m^2-9[4mn+m^2-3(2m^2+mn)]+(-10m^2-2mn)=8m²-36mn-9m²+54m²+27mn-10m²-2mn=43m²-11mn2. 1/4a^2b^2[3ab(a+b)-5a(ab-b^2)]=a²b²/4(3a²b+3ab²-5a²b+5ab²)...