计算x+3y/x²-y²+x+2y/y²-x²+2x-3y/x²-y&

计算3x[xy-2x(1/y-x/3]+3y(x²-y²) 计算(x²/x+2y)-x+2y-2 (2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) 急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy) (x-y)X(2x-2y)²X(3x-3y)² [(3x+y)²-(3x-y)²]÷(4x-2y)计算 怎么做? 数学用乘法公式计算(x+y+1)(x+y-1)(2x-y-3)² (x-y)·2(x-y)²·3(x-y)³ 计算 因式分解:x²(x-y)+(y-x) 有这样一道题:"计算(2*x*x*x-3*x*x*y-2*x*y*y)-(x*x*x-2*x*y*y+y*y*y)+【- 计算(x+y)(x+y)^2(-x-y)^3