计算(3a+2)(3a-2)-5a(a-1)-(2a-1)的平方

问题描述:

计算(3a+2)(3a-2)-5a(a-1)-(2a-1)的平方

(3a+2)(3a-2)-5a(a-1)-(2a-1)^2=9a^2-4-5a^2+5a-4a^2+4a-1=9a-5