1.x+x+x+y+y=6.4 y+y+y+x+x=7.1 x= ( ) y=( ) 2.1,4,7,10,13……这串
1.x+x+x+y+y=6.4 y+y+y+x+x=7.1 x= ( ) y=( ) 2.1,4,7,10,13……这串
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
X+Y=7(100X+Y)-(10Y+X)=(10Y+X)-(10X+Y)
) 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)=?
根据x+x+x+y+y=54,x+x+y+y+y=56,求出x.y的值
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)