4(X+2Y)^2-9(X-Y)^2

已知4x=9y求(1)x+y/y (2)y-x/2x x^2-y^2/x+y-4x(x-y)+y^2/2x-y, (2x-y)^2-4(x-y)(x+2y) (2x-y)²-4(x-y)(x+2y) 化简：（2x-y)²-4(x-y)(x+y) {(z+y)(x-y)-(x-y)的2次方+2y(x-y)}除以4y x+2y+4y^2/x-y+4x^y/4y^2-x^2 4(x+y)^2-12(x+y)(x-y)+9(+y)^2因式分解, 4x(y-x)-y^2因式分解 (x+3y-4)(2x-y) 1、x(x-y)(x+y)-x(x+y)^2 x/x-y*y^2/x+y-x^3y2/x^4-y^4/x^2/x^2+y^2