已知x²+y²-4x+6y+13=0,求(x²+2y)/(x²-3y²
已知x²+y²+13-4x+6y=0,求(2x-y)²-2(2x-y)(x+2y)+(x+
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
已知x²+4y²-6x+8y+13=0,求x-y/x+y的值.
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-4x+6y+13=0,求(x²+2y)/(x²-3y²
已知4x²+y²-4x-6y+10=0求(2/3x(√9x)+(y²√x/y³)
已知x²+4y+y²—6y+13=0,求2x+3y的值
已知X²+Y²-6X+4Y+13=0,求2X+3Y
已知:x2+4x+y2-6y+13=0,求(x-2y)/(x²+y²)
已知x²+4x+y²+6y+13=0,求x-y+(2y²/x+y) 请在10;20分前回答
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y