x+2y+x-2y分之4y平方-x-4y平方分之4x平方y
问题描述：
x+2y+x-2y分之4y平方-x-4y平方分之4x平方y
答
x+2y+4y^2/(x-2y)-4x^2y/(x-4y^2)=x+2y+4y^2/(x-2y)-4x^2y/[(x+2y)(x-2y)] 通分,分母为[(x+2y)(x-2y)]=(x+2y)(x+2y)(x-2y)/[(x+2y)(x-2y)]+[4y^2(x+2y)]/[(x+2y)(x-2y)]-4x^2y/[(x+2y)(x-2y)]=[(x+2y)^2(x-2y)+4y^2(...