(-4+3y)(-3y-4x)-(2x+3y)(8x-9y) 求答案

已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y( 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) x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8 (x+3y-4)(2x-y) 9y=3x-(x-1),4(x+y)-(2x+4)=8y 已知2x+2y=-8,4x+y=15求（x-y)^-(3x+2y)^ 已知x/y=3/2求代数式4x-9y/2x+3y 已知|2-x|与|x-y+4|互为相反数,求代数式3(x-y)-5(x-y)-3(x-y)+(y-x)-4(x+y)+3 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2 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