(x+y)²=10,(x-y)²=2求x²+y²,xy的值
X²+Y²=9.(X+Y)²=13 求XY和X+Y的值
已知x+y=-10,xy=16求下列的值 ①x²+y² ②(x-y)² ③(x+2)(y+
已知x-3y=0,y≠0,求x²-2xy+y²分之2x+y×(x-y)的值
已知x+y=10,xy=4,求x²+y²和(x-y)²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=5,xy=6,求(x+y)²-2x-2y+1的值
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
4/X+1/Y=2,XY=-1,求代数式4Y-X/X-2Y/(x+2y-12Y²/x-2y)的值
已知x/2=y/3(xy≠0),求x²-2xy-3y²/x²-6xy-7y²的值