已知x²+y²+6x-8x+25=0,求(x/x²-y² - 1/x+y)÷y/
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
x²+y²-6x+8y+25=0求(x-y)-²
已知x²+4y²-6x+8y+13=0,求x-y/x+y的值.
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知x,y满足x²+y²-4x-6y+13=0,求(- y/x^3)^3÷(- 1/xy)^4.(x
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x.
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知x²+y²+13-4x+6y=0,求(2x-y)²-2(2x-y)(x+2y)+(x+
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²