Lời giải:
$xy=x-y$
$\Rightarrow xy-x+y=0$
$\Rightarrow x(y-1)+(y-1)=-1$
$\Rightarrow (x+1)(y-1)=-1$
Với $x,y$ nguyên thì $x+1, y-1$ nguyên. Mà tích của chúng bằng -1 nên ta xét các TH sau:
TH1: $x+1=1, y-1=-1\Rightarrow x=0; y=0$
TH2: $x+1=-1, y-1=1\Rightarrow x=-2; y=2$
1. tim cac cap so nguyen duong (x, y) sao cho:
2 x3 + xy = 11
2. tim cac cap so nguyen duong (x, y, z)sao cho:
x + y + z = x*y*z
3. tim x thuoc z, biet;
|x| = -2003
|x| = |-2003|
minh dang can gap lam. chieu mai phai nop rui
Tim tat ca cac cap so nguyen x,y sao cho xy-2x+y+1=0
Tim tat ca cac cap so nguyen x,y sao cho
c) (x - 2) (2y + 1)=4
tim tat ca cac cap so nguyen x, y sao cho : xy - 2x + y + 1 = 0
tim cac cap so nguyen x,y biet /x/+/y/=-5
Tim tat ca cac cap so nguyen x,y sao cho
a) xy = 3
b) x(2y - 1)=8
cho 2 so x;y la cac so nguyen sao cho :/x/ +/y/ = 2 so cap (x;y) thoa man la
Tim cac gia tri nguyen cua x biet
a, Y=5x+9/ x+3
b, Tim cac cap so nguyen x , y thoa mai he thuc :
(2x-1).(y+4)
Tim cac cap so nguyen x;y biet : (2x-1)*(y-4)=-13
