Đáp án+Giải thích các bước giải:
`(x + 4) . (y + 5) = 18`$\\$`=>(x + 4), (y + 5)\inƯ(18)={+-1;+-2;+-3;+-6;+-9;+-18}`$\\$`\text{ta có bảng:}`\begin{array}{|c|c|c|}\hline \text{x+4}&\text{1}&\text{-1}&\text{2}&\text{-2}&\text{3}&\text{-3}&\text{6}&\text{-6}&\text{9}&\text{-9}&\text{18}&\text{-18}\\\hline\text{y+5}&\text{18}&\text{-18}&\text{9}&\text{-9}&\text{6}&\text{-6}&\text{3}&\text{-3}&\text{2}&\text{-2}&\text{1}&\text{-1}\\\hline\text{x}&\text{-3}&\text{-4}&\text{-2}&\text{-6}&\text{-1}&\text{-7}&\text{2}&\text{-10}&\text{5}&\text{-13}&\text{14}&\text{-22}\\\hline \text{y}&\text{13}&\text{-23}&\text{4}&\text{-14}&\text{1}&\text{-11}&\text{-2}&\text{-8}&\text{-3}&\text{-7}&\text{-4}&\text{-5}\\\hline\end{array}
