（1）x-y/x-2y÷x^2-y^2/x^2-4xy+4y^2

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/17 14:10:30

（1）x-y/x-2y÷x^2-y^2/x^2-4xy+4y^2
(2)3a/a+b - 3b/a+b
(3)x+3/x^2-9 + 3/x-3
(4)x^2/x+y - x+y
(5)(a^2/a-3 + 9/3-a)÷a+3/a

（1）x-y/x-2y÷x^2-y^2/x^2-4xy+4y^2=(x-y)/(x-2y)÷(x+y)(x-y)/(x-2y)²
=(x-y)/(x-2y)*(x-2y)²/(x+y)(x-y)
=(x-2y)/(x+y)
(2)3a/a+b - 3b/a+b=3a/(a+b)+3b/(a+b)
=3(a+b)/(a+b)
=3
(3)x+3/x^2-9 + 3/x-3=(x+3)/[(x+3)(x-3)]+3/(x-3)
=1/(x-3)+3/(x-3)
=4/(x-3)
(4)x^2/x+y - x+y=x²/(x+y)-(x-y)
=(x²-x²+y²)/(x+y)
=y²/(x+y)
(5)(a^2/a-3 + 9/3-a)÷a+3/a
=[a²/(a-3)+9/(3-a)]÷(a+3)/a
=[a²/(a-3)-9/(a-3)]*a/(a+3)
=[(a²-9)/(a-3)]*a/(a+3)
=[(a+3)(a-3)/(a-3)]*a/(a+3)
=(a+3)*a/(a+3)
=a

（1）x-y/x-2y÷x^2-y^2/x^2-4xy+4y^2 先化简,再求值(x-y/x+y)^2÷(y-x/x^2+2xy+y^2)^2*1/x+y,其中x=-4,y=1 x^2y+4xy+4y 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? (2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)+2x^4y^2÷(xy)^2 (x^-4y^)/(x^+2xy+y^)/(x+2y)/(2x^+2xy) 计算:4xy-(x+y)^2/xy(x+y)(x-y)÷x^2+xy-2y^2/x^2y+2xy^2 x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y 计算（1）x/x+y-x/x-y （2）a+2+4/a+2 （3）x^2-y^2/xy÷(x+y) 已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y² 因式分解：x×x-xy-2y×y-x-y [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y-