当x=0,y=15.x=2,y=20.x=4,y=15.x=6,y=30.x=8,y=35
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
当x=0,y=15.x=2,y=20.x=4,y=15.x=6,y=30.x=8,y=35
[x(x-y)-y(x-y)+(x+y)(x-y)]÷2x其中x=2012 y=2013
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
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
当x、y满足x>=0,y>=x,2x+y+k
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x.x+y.y+8x+6y+25=0,求代数式(x.x-4y.y)/(x.x+4xy+4y.y)-x/(x+2y)的
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
[(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x=