计算x+y+2y²/x-y,

计算(x²/x+2y)-x+2y-2 计算:(-x-2y) * (3x-y) 计算:(x-y)^2*(y-x)^2*(x-y)^6 计算(x+y)(x+y)^2(-x-y)^3 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3x[xy-2x(1/y-x/3]+3y(x²-y²) x-y/xy-y^2计算 计算：[(x＋¼y)＋(x-¼y)](2x²-1/8y²) [(3x+y)²-(3x-y)²]÷(4x-2y)计算 怎么做? 计算(x-2y-1)(x-2y+1)-(x-2y-1)² 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