-8x^2y^4*3x/4y^6/(-x^2y/6z)

81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 4x-3y/x-2y÷6y-8x/y-2x 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y(x-y)^2）/2（x-y)^2 (3x-4y)(5x-4y)-(7x-8y)(6y-5x) {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 （y-x）^4（x-y）^3+2（x-y）^6（y-x） 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+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 x^3+2x^2y-4x-8y 因式分解：a(x-y)^2+b(y-x)^3 4(x-y)^2+8(y-x)(x+y)1.a(x-y)^2+b(y-x)^3 2.4(x-y)^2+8(y-x)(x+y) 1.(x^3-x^2-4x+1)/(x^2-3x+2)-(x^3-2x^2-9x+21)/（x^2-5x+6）+（x^2-3x+8）/（x^2-4x+3）2.{(x^2)/（x-y)}*{y/(x+y)}-{(x^4y)/(x^4-y^4)}÷{（x^2/x^2+y^2）^2} (1)x^2*x^8+x^13/x^3 (2)a^19/a^12/a^3 (3) (x-2y)^5/(2y-x)^3 (4)(x-y)^5/(x-y) (5)(x-y)^6/(y-x)^4 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y)