2008^2 -2007×2009 (x+3)^2-(x-1)(x-2) (x ^2y) ^3·(-2y ^2)^2÷(
(x-y)(x-2y)-(3x-2y)(x-3y)
((x+2y)x^2+(x-y)(3x-y)-5y^2)÷2x
2(x-y)+3(x+y)2-5(x-y)-8(x+y)2-(x-y)
(X-3Y)(X+3Y)-(X+2Y)(X-4Y)-(2X-Y)2的平方
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
1) (x+y)^2-(x+y)^3 2) (x-y)^2-(x-y)^3 3)(x-y)^2-(y-x)^3 因式分解
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
先化简,再求值 (1)[(x-y)的平方+(x+y)(x-y)]÷2x 其中X=2010,y=2009 (2)y(x+y
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
计算:1/(2x) - 1/(x+y)((x+y)/(2x) - x - y)
7x+[-3x-3(x-2y)]-[5x-(2x-y)]
计算:(3x-y)2-(2x+y)2+5x(y-x)