已知：x+y=2,2y²-y-4=0,求y-x/y的值

已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 就是已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y /4y就是除以4y 已知x/y=3,求x²+2xy-3y²/x²-2xy+y² 已知x²+4x+y²-2y+5=0,则x²+y²= 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 已知:x²-6x+8y+y²+25=0,求x²+2xy+y² 已知2x+3y=0,求代数式1.5x+4y/3x-2y 2.x²+xy-y²/x²-xy+y² 已知3x²+xy-2y²=0(x≠0,y≠0),求x/y-y/x-x²+y²/xy的值 已知x²+y²-6x+4y+13=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)²已知x²+y²-6x+4y+13=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)² 已知,x²+2y²-2xy-4y+4=0,求x²+y²的值 已知2x-y=10 【（x²+y²）-（x-y)²+2y（x-y）】÷4y 过程 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² + xY- 2Y² =求x² - 4x Y+ Y² = 已知x²+y²-4x+6y+13=0,求x²+2y/x²-3y²的值 已知x²+y²-2x-4y+5=0,求分式y/x-x/y的值. 1.已知x/x-1=（y²+4y-1）/（y²+4y-2）,则y²+4y-x的值为多少? 2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y 已知x²-4x+y²-10y+29=0.求x²y²+2x³y²+[x²]²y²的值. 已知4x²-3y²=7,3y²+2y²=19,求14x²-2y的值