已知x+y=9 xy=10,求x²+y²,x³+y³,x^4+y^4,
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
2x+y=0,求4x²+2xy(x+y)+y³
已知非零有理数x,y满足x²-4xy+4y²=0,求x-y/x+y-y-x/x+y的值.
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知2x+y+4,xy=2,求-4x²y²-y³x-4x³y的值
已知:x/y=4/5,求y²/(x²-xy+y²)的值
已知X²+3XY-4Y²=0(Y≠0)求X-Y/X+Y
已知x³=10-y³,x²y-xy²=-3,求代数式(x³-y
已知x+y=2,xy=1/2,求x³y+2x²y²+xy³