0.5x+0.7y=35,x+0.4y=40.求x=?,y=?
0.5x+0.7y=35,x+0.4y=40.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)
0.58=(0.5x+0.7y)/(x+y)求X比y怎么求
老师.0.58=(0.5x+0.7y)/(x+y)求X比y怎么求
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
已知X,Y独立,P(x)=0.5,p(x+y)=0.7,求p(y).
求微分方程y'=x/y+y/x的通解
y=2x*arctan(y/x),求y‘’