tim x y 2x+(x^2+1)(y^2-6y+8)
cho x,y thoa man: x^2+y^2= x+y .tim MIN ,MAX cua B=x-y
tim x ,y la so nguyen to biet : x^2 - 6y^2 -1 =0
tim max hoac min cua x^2-2*x+y^2-4*y+16
tim x,y,z
10x=6y và 2x^2-y^2=-28
tim cac so x y z biet 4x bang 6y bang 8z va x-y bang 2
tim x y z x/2=y/3 y/4=z/5 va x^2-y^2=16
3x/8=3y/6y=3z/216 va 2x^2+2y^2-z^2=1
toan 7 tim x,y,z biet (xy/2y+4x)=(yz/4z+6y)=(zx/6x+2z)=(x^2+y^2+z^2)/2^2+4^2+6^2
tim x,y,z biet 3y\(^2\)+x\(^2\)+2xy+2x+6y+3=0
