x^2-9y^2

9(x-y)-12(y-x)^2 (x+y)^2+6(x+y)+9 (x+y)^2-9(x+y)+18 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 (x-2y)^2-6(2y-x)(x+y)+9(x+y)^2因式分解 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 81/8*(-x-y)^6*(x-y)^3*4/9(x+y)^4*(y-x)^2 计算(x-y)^7÷(y-x)^6+9-x-y)^3÷(x+y)^2 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 9(x+y)-2(x+y)-6(x+y)+18(x+y)合并同类项 合并同类项：9(x+y)-2(x+y)-6(x+y)+18(x+y) 化简y(x+y)+(x+y)(x-y)-x^2 化简：x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y) 先化简再求值 x(9x-y)-y(y-x)+(x-y)的平方,其中x=-1,y=2 (x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) x^3y^2+6x^2y+9x 因式分解x(x+y)(x-y)-x(x+y)^2