x-y=10 xy=24 求x²+y²
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
x/y=3,求x²+y²-xy/x²-y²的值.
2x+y=0,求4x²+2xy(x+y)+y³
已知X+y=10,XY=24,求(X-Y)(X-Y)的值
已知 x²-xy=40,xy-y²=10,求代数式 x²-y² 和 x²
已知实数xy,满足10x²-2xy+y²+6x+1=0,求x+y
已知(x+3)+丨X-y+10丨=0 ,求5x²y-[2x²y-(3xy-xy²)-3x&
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
4x²+8xy=y²+xy,求x:y=?