X+Y=10009.93%x+25%y=100
X+Y=7(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y)
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
) y=cos(x-y)
x+y=5; x^y+y^x=17
因式分解下列式子:x(x-y)+y(y-x)=?
If two even number x,y satisfy equation x×x+100=y×y,x
已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值
x,y属于R*,且x+y=1,求证:(1)(x+1/x)(y+1/y)≥25/4 (2)(x+1/x)^2+(y+1/y
已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
根据x+x+x+y+y=54,x+x+y+y+y=56,求出x.y的值