已知(x y)²=25,(x-y)²=9求x² y²的值
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²=25,x+y=7,求x-y的值.
已知2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y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x²+y²=25,x+y=7,且x>y,求x-y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|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,y≠0,求x²-2xy+y²分之2x+y×(x-y)的值
已知方程组2x+y=6 x-3y=1,求7y(x-3y)²-2(3y-x)³的值
已知(x+y)²=25,xy=6,求x-y的值.
已知x²-y²=12,x+y=6,求x,y的值