已知X/Y=3,求X·X+2XY-3Y·Y/X·X-XY+Y·Y
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知x-y=-2/3,求(x·x+y.y)的完全平方-4xy(x·x+y·y)+4x·x·y·y的值
已知x2+y2-2x+4y+5=0,求(x^4-y^4)/(2x^2+xy-y^2)·[(2x-y)/(xy-y^2)]
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知x+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.
已知x^2+y^2-4x+6y+13=0求(xy+y^2/5x^2-5xy+xy+y^2)·(5/x+y)-(y/x-y
已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y)
已知:x/y=-2,求x^2-2xy-3y^2/x^-6xy
已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y)