y=(20+x)(80-2x) =-2x²+40x+1600怎么算
y=(x^2+x)/(x+1)
整数x,y满足方程2xy+x+y=83,则x+y怎么算
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
y=-(2x+3)/x^2求导怎么算?
y=-x²-2x+3怎么解
y=(x+1)(x+2)的反函数怎么算
y= x/x-2的 导数 怎么算?
x²-2x-x+2=0怎么算
x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20
{(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
(x+y)(x+2y)(x+3y)(x+4y)=-40