3(2X+1)(2X-1)-4(3X+2)(3X-2) =3(4x的平方-1)-4(9x的平方-4)=12x的平方-3-36x的平方+16=13-24x的平方
3(2X+1)(2X-1)-4(3X+2)(3X-2)=3(4x^2-1)-4(9x^2-4)=12x^2-3-36x^2+16=13-24x^2
3(2X+1)(2X-1)-4(3X+2)(3X-2)=3[(2X)^2-1]-4[(3X)^2-2^2]=12X^2-3-36X^2+16=13-24X^2