tim cac so nguyen x,y thoa man: 1/x-1/3=1/y voi x,y khac 0
tim cac so huu ti x y thoa man x+y va 1/x +1/y nguyen duong
tim cac so nguyen x, y thoa man x>y>1 va 2x + 2y + 1 chia het cho xy
tim tat ca cac cap so nguyen x,y thoa man 2^x+1.3^y=12^x
cho x,y,z la cac so huu ti duong thoa man x+1/yz y +1/xz z+1/xy la cac so nguyen tim gia tri lon nhat cua bieu thuc A=x+y^2+z^3
tim cac cap so nguyen x , y thoa man : 2 . ( xy - 3 ) = x
tim cac so nguyen x ,y,z thoa man /x-y/+/y-z/+/z-x/=2015
Tim cac so nguyen duong x;y;z thoa man x!+y!=10.z+9
tim cac so nguyen to x y z thoa man 3(x+y+z)=xyz
