(x=0.5y=6.5)(x=1y=7.5)(x=1.5y=8.5)(x=2y=9.5)(x=2.5y=10.5)写出x
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
y'-2y=(e^x)-x
y'+2y/x=x通解
y=(x^2+x)/(x+1)
y*y*y*y+2x*x*x*x=4x*x*y 求x等于几,y等于几,写出所有选项!
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知4x=9y求(1)x+y/y (2)y-x/2x