0.1x+0.3y=2.5 0.1x-0.1y=2.1,求x,y
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
求y'=y/(y-x)
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)
x+x+x+y=52 y+y+y+x=36求x
(x*x+y*y)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少
0.1y=2x,5x+y=5
已知二元一次方程组0.2x+0.1y=0.7,0.1x+0.2y=0.8,求x-y和x+y的值
求微分方程y'=x/y+y/x的通解
y=2x*arctan(y/x),求y‘’
已知:4x = 5y,求(x+y) :y
|x-y |=x-y |x |=1999 |y |2000,求x+y的值