x+x+x-y-y=12 y+y+y-x-x=2 求x=?y=?奥数解法
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)
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
(x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少
高数:已知f(x+y,y)=x^2+y^2,求f(x,y)
y=x+1/x详细解法
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
求y'=y/(y-x)
x2-x-y2-y 解法:=(x2-y2)-(x+y) =(x+y)(x-y)-(x+y) =(x+y)(x-y-1)
y=2x*arctan(y/x),求y‘’
已知4x=9y求(1)x+y/y (2)y-x/2x
x+x+x+y=52 y+y+y+x=36求x