-(3-2a的平方)-(2a的平方-3a-7)=

问题描述:

-(3-2a的平方)-(2a的平方-3a-7)=

-(3-2a^2)-(2a^2-3a-7)
=-3+2a^2-2a^2+3a+7
=3a+7-3
=3a+4