Chứng minh đẳng thức: 4x^2-(x-3)^2/9(x^2-1)-x^2-9/(2x+3)^2-x^2+(2x-3)^2-x^2/4x^2-(x+3)^2
Giải thích
4x2−(x−3)29(x2−1)−x2−9(2x+3)2−x2+(2x−3)2−x24x2−(x+3)2=(2x−x+3)(2x+x−3)9(x−1)(x+1)−(x−3)(x+3)(2x+3−x)(2x+3+x)+(2x−3−x)(2x−3+x)(2x−x−3)(2x+x+3)ư
=3(x+3)(x−1)9(x−1)(x+1)−(x−3)(x+3)3(x+3)(x+1)+3(x−3)(x−1)3(x−3)(x+1)=x+33(x+1)−x−33(x+1)+3(x−1)3(x+1)=x+3−x+3+3x−33(x+1)=3x+33x+3=1