\(\left(x+4\right)\left(y-1\right)=13=1\cdot13=13\cdot1=-13\cdot-1=-1\cdot-13\)
Ta có bảng sau:
x + 4 | 1 | 13 | -13 | -1 |
y - 1 | 13 | 1 | -1 | -13 |
x | -3 | 9 | -17 | -5 |
y | 14 | 2 | 0 | -12 |
Vậy: ...
_______________________
\(xy-3x+y=20\)
\(\Rightarrow x\left(y-3\right)+y-3=17\)
\(\Rightarrow\left(x+1\right)\left(y-3\right)=17=1\cdot17=17\cdot1=-1\cdot-17=-17\cdot-1\)
Ta có bảng sau:
x + 1 | 1 | 17 | -1 | -17 |
y - 3 | 17 | 1 | -17 | -1 |
x | 0 | 16 | -2 | -18 |
y | 20 | 4 | -14 | 2 |
Vậy: ...