x+[y]=201.1,{x}+y=20.11,则x+y=
二元函数f(x,y)=x+y/x-y,求f(y/x,x/y)
1.已知1/x+1/y=-1/x+y,则y/x+x/y=?
已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy)
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
实数x,y满足tanx=x,tany=y,且|x|≠|y|,则sin(x+y)x+y−sin(x−y)x−y
现规定一种新运算:x*y=(x+y)-(x-y),其中x,y为有理数,则x*y+(x+y)*(x-y)等于多少
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
已知实数x,y满足|x|+x+y=10、x+|y|-y=12,则x+y的值?
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
) y=cos(x-y)
x+y=5; x^y+y^x=17