3x÷(x-4y)+x+y÷(4y-x)-7y÷(x-4y)解方程

(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)+2x^4y^2÷(xy)^2 数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y [(x+2y)²-（x+y)(3x-y)-5y²]÷(2x),其中x,y满足x²+4x+y 计算 [12(x+y)³(y-x)]³÷[4(x+y)²（x-y)]² 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 【(3x-2y)^2-(4x+y)(4y-x)】÷3x 化简：[(2x-y)平方+（2x+y)(2x-y)-4x(x-y+1)]÷2x x-4y分之3x + 4y-x分之x+y - x*x-4y分之7y x(x-y)+4(y-x)因式分解 计算：(x-y)^7÷(y-x)^6+(-x-y)^3÷(x+y)^2 解方程x+y+(x+y/2)=15 3x+5y+4(x+y/2)=62 (3x-4y)(5x-4y)-(7x-8y)(6y-5x)