Question

3x+4y-xy=16

Answer 1

3x+4y-xy=16 
<=>x(3-y)-12+4y=16-12 
<=>x(3-y)-4(3-y)=4 
<=>(3-y)(x-4)=4 
=>(3-y),(x-4) thuoc U(4)=(1,-1,2,-2,4,-4)
Đáp số: 
(x;y)={(8;2);(5;-1);(0;4);(3;7)}