9(x+y)2-(x-y)2怎么算,还有：（x-2）（x-4）+1和：（x+y）²-4（x+y-1）

9(x+y)2-(x-y)2怎么算,还有：（x-2）（x-4）+1和：（x+y）²-4（x+y-1） x-y+2y的平方/x+y怎么算? [(2X+Y)*(2X+Y)-Y(Y+4X)]/2X 怎么算? (x-y)^4·(x-y)-2(y-x)³·（y-x)²怎么算, 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? （x+y)²+2（y-x） 因式分解 怎么弄 我这还有几道题（x+y)²-(x+y)(x-z)+(x+y)(y+z)X(X-a)(x-b)-y(a-x)(b-x)x(x+y)(x-y)-x(x+y)²（2a+b)(2a-3b)-3b(2a+b)(a+b)²-9(a-b)²(a²+b²)²-a²b²9（x-y）-y& [(x+y)的平方—(x+y)(x—y)]除以2y怎么算 (x+2y)^2-(2x-y)^2 还有9（2x-y）^2-4(x+2y)^2 (2x+y-1)(2x+y-1)怎么算 |x-y+2|=|x+y+2|怎么算? (2x-3y)-(5x-y)怎么算 (x-y)^2(y-x)^3怎么算啊, (x+y)^2-6(x+y)+9怎么因式分解 怎么因式分解6(x-y)-9-(x-y)∧2 2xy/(x+y)(x+y)与x/(x+y)(x-y)怎么通分 （x-y)^3*(x-y)^2*(y-x)这道题怎么算（x-y)^3*(x-y)^2*(y-x)看不懂？（x-y)^3乘(x-y)^2乘(y-x)总可以了吧 a=x+y-z/2英文怎么读?还有x>=y? y=(1/2)^x奇偶性怎么判断 还有y=-x^3的奇偶性 .