1.Y^2-9(x+y)^2
1.Y^2-9(x+y)^2
1.[(x-y)^2-2(y -x)]÷(x-y)
1.(x-2y)(x+2y)-(x平方+y)(x平方-y) 2.(2x-y)(y+2x)-(2y+x)(2y-x)
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
已知4x=9y求(1)x+y/y (2)y-x/2x
先化简 再求值(x-2y)(2y-x)+(2x+y)(2x-y )-(x-2y)(2x+y) 其中x=-2,y=-1.
化简:x-y/x+3y÷x^-y^2/x^2+6xy+9y^2-(xy/x+y)
1.(x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2)
1、x(x-y)(x+y)-x(x+y)^2
[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y
4(x+y)^2-12(x+y)(x-y)+9(+y)^2因式分解,
因式分解.1.ax^2+(a^2+1)x+a 2.3x^2+5xy-2y^2+x+9y-4 3.4(x-y+1)+y(y