(x+y)²=1,(x-y)²=49,求x²+y²与xy的值
(x+y)²=1,(x-y)²=49,求x²+y²与xy的值
已知(x+y)²=1 (x-y)²=49,求x²+y²与xy的值
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
x/y=3,求x²+y²-xy/x²-y²的值.
(x+y)²=1 (x-y)²=49 求x²+y²与xy的值
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值
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.
若xy=3,x²+y²=10,求x+y与x-y的值
若正数x,y满足x²-y²=2xy,求(x-y)/(x+y)的值
正数x,y满足x²-y²=2xy,求x-y/x+y的值
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x+y=1 xy=-1/2 利用因式分解求x(x+y)(x-y)-x(x+y)²的值