已知3x-y=1/16,xy=2,求6x^4y^3-2x^3y^4
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x-y=3,xy=1,求(-2x+2x+3y)-(3xy+2y-2x)-(x+4y+xy)
已知x,y>0 2x+y+3=xy 求5x+4y最小值
已知1/x-1/y=3,求(3x+4xy-3y)/(x-2xy-y)的值
已知1/x+1/y=3,求3x-4xy+3y/(x+2xy+y)的值
已知;x+y=4,x-y的绝对值=6,求xy(y的平方+y)-y的平方(xy+2x)-3xy
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
x^+2xy+y^+4=16 x^-2xy+y^=16 求(3xy+6y^)+|x^-(2xy+2y^-3x^)|的值