若2x-y=3,试求-5-4x+2y的值

若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 若(x-y)乘(x+y)=5,(x+y)^2=4,试求x-y的值 已知(x+2y)(2x-3y)=y(y-4x),试求x/y的值 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值 若x-y=2(x+y),求代数式x-y/x+y+x+y/x-y求代数式 x+y分之x-y+x-y分之x+y 已知:y=ax的3次方+bx+3,当x=-1/2时,y=-7,试求x=1/2时,y的值 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 若x^2+y^2+5/4=2x+y,求x^Y+y^x的值? 若x*x-4y*y=-15,x+2y=3,求x和y的值 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值. 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 若2x-y=3,试求-5-4x+2y的值