(x²+y²-3)²=16求x²+y²的值
已知x,y的值满足方程组x+2y=3,x-y=-2,求x/(x-y)²+x²-y²/(x+
x/y=3,求x²+y²-xy/x²-y²的值.
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知x+3y=2,求代数式(x²-y²/x+y)-【2(x+y)】的值
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
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x²+x*y=-1,x*y+y²=2,试求2x²-x*y-3y²的值
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-3y=0,求(x²-2xy+y²/x-y)-2y的值
已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值
已知x²+y²=25,x+y=7,求x-y的值.