计算 x+2y+﹙4y²/x-2y﹚+﹙4x²y/4y²-x²)
问题描述:
计算 x+2y+﹙4y²/x-2y﹚+﹙4x²y/4y²-x²)
答
x+2y+﹙4y²/x-2y﹚+﹙4x²y/4y²-x²)
=[(x+2y)(x-2y) +4y²]/(x-2y﹚+ 4x²y/(4y²-x²)
=(x²-4y² +4y²)/(x-2y﹚+ 4x²y/[(2y+x)(2y-x)]
=x²/(x-2y﹚- 4x²y/[(x+2y)(x- 2y)]
=[x²(x+2y﹚- 4x²y]/[(x+2y)(x- 2y)]
=(x³-2x²y)/[(x+2y)(x- 2y)]
=x²(x-2y)/[(x+2y)(x- 2y)]
=x²/(x+2y)