（9x^4y^5+45x^2y^4)÷(-3xy^2)^2

[(x+y)(x-y)-(x-y)²+2y(x-y)]÷4y 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 [(x-2y)(x+2y)+4(x-y)^2]÷5y 4x+2y-5x-y 因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) x²/xy-x/y 3x/4x+y - x-2y/4x+y (1-y/y+x)÷x/y²-x² 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} （4x-3y)(5x+2y)-2x(9x-5y) 等于多少 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 计算.2x÷x/5x+3y^2-4y+4/2y-6·1/y+3÷12-6y/9-y^2 化简【(x²+y²)-(x-y)²+2y(x-y)】÷4y 已知x²+4y²-4x+4y+5=0,求(2x-y)(x+y)/x四次方-y四次方×xy-y²/2x-y÷(y/x²+y²)² [4y(2x-y)-2x(2x-y)]÷(2x-y) [4y（2x-y)-2x(2x-y)]÷（2x-y)怎么做 4x-3y/x-2y÷6y-8x/y-2x 计算：[（x+y）³-2(x+y)²-4(x+y)]÷（x+y) 计算[(x+y)的立方-2(x+y)的平方-4(x+y)]÷(-x-y) 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2