已知2x+y=8,4x²-y²=90,求x,y的值
已知x² +y²+5/4=2x+y,求y-x的值
已知x²+4y²-6x+8y+13=0,求x-y/x+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.
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y的值
已知2x-y=10,求代数式[(x²+y²)-(x-y)²+2y(x-y)]÷4y的值?
已知2x-y=10,求代数式[x²+y²-(x-y)²+2y(x-y)]÷4y的值
已知x-y=4,x²-y²=20,求x-y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+
已知x+y/y=11/8,求x-y/x+2y的值.
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²的值