已知3x^2-xy-4y^2=0,且x+y≠0,说明y=3/4x
已知x-y=4xy且xy≠0,求代数式-x-2xy+y分之2x+3xy-2y的值
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知xy≠0,且2x+3xy-2y=0,求(x+y)/(x-y)的值.
已知3x^2-xy-4y^2=0,且x≠y求x-2y/x+2y的值
已知x,y>0 2x+y+3=xy 求5x+4y最小值
(1)已知x-y=6,xy=4,求xy^-1+x^-1y的值; (2)已知x^2+y^2=3xy且xy≠0,求x^2y^
已知x^2+3xy-4y^2=0(y≠0),求x-y/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^2-xy+3y^2=0 且xy不等于0 求x/y+y/x 的值
已知4x-y^2-2x+y=0,且y≠2x,求代数式(4x^2*y+2x*y^2-3xy)/2xy的值 请多指教!
已知(x+2)^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy
已知(x+2)^2+|x+y+5|=0,求3x^2y+{-2X^2y-[-2xy+(x^2y-4x^2)]-xy}