计算:(3x-y+4)(3x+y-4)

(x-3y)(y+2x)-(4y-3x)(3x+4y)计算 计算（2x-3y)(x+4y)-(3x+y)(x-2y) 计算【3(x-y)^2(x+y)^-2/4(x+y)^2(x-y)^-2】^-2 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2) 计算:[(2x - 3y)^2 - (x-y)(4x+2y)] / 2y 计算：3x-2y- [-4x+(z+3y)] 计算（4x^2y-9y)/(2x+3) 计算(3x+y-2)(4x-y+2) 计算：（3x-4y）-[-（2y+x）+（x-3y）]-6x 计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8 (x-2y)2+(x+2y)(x-2y)-(x-3y)(x-y)计算结果是什么?x等于-4,y等于0.5代入后是多少第一 计算：2x^2y^3+(4x^2y^3)-(-3x^2y^3)