已知x,y满足x²-4xy+4y²-5（x-2y）=3,求2x-4y值

已知x,y满足x²-4xy+4y²-5（x-2y）=3,求2x-4y值 已知实数x、y满足5x²-3xy+1/2y²-2x+1/2y+1/4=0 求x、y的值 已知实数x,y满足x²+4y²=4.求f(x,y)=x²+2xy+4y²+x+2 已知x,y满足x²+y²+5/4=2x+y,求代数式（x+y)·xy的值. 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 已知非零实数x,y满足x²-4xy+4y²=0,求分式2x-y除以2x+y的值 已知2x+3y=0,求代数式1.5x+4y/3x-2y 2.x²+xy-y²/x²-xy+ 已知实数X,Y,Z满足 X²-6XY+10Y²+4Y+∣Z²-3Z+2∣+4=0,求（X+ 问已知x²+y²=7,xy=－2,求5x²-3xy-4y²-11xy-7x&su 已知x-2y=3,x²-2xy+4y²=11,求①xy ②x²y-2xy² 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值