（-4x-y）(-5x+2y)

(3x-y)²-2x（4x-5y）-（x+2y）² .先化简再求值：（2x+y）（2x+y)-(2x-y)平方其中X,Y满足X平方+Y平方-2X+4Y+5=0 1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y 2x^2y×（-8y^2）+4x^2y×5y^2 计算4（x+y）^5（x-y）^4÷[2（x+y）³*（y-x）²] 5/12[-4/3（x-y）^3] *（x+y）^2 * (-x-y)^3 * 5/6(y-x)^2 （x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3) 1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y 2.（2(x-y)^3-8(x-y）^2(x+y)+6y( 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 （x-2y）²+（2x-4y)(x+y)+(x+y)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) x^8-x^7y+x^6y^2-x^5y^3+x^4y^4-x^3y^5+x^2y^-xy^7+y^8