- Vì : \(a\in N\Rightarrow a+5\in N\)
- Vì : \(b\in N\Rightarrow b-3\in N\left(b-3\ge3\right)\)
\(\Rightarrow a+5\) và \(b-3\inƯ\left(15\right)\)
Mà : \(Ư\left(15\right)=\left\{1;3;5;15\right\}\)
Mà : \(b-3\ge3\)
Nên ta có bảng sau :
| a + 5 | 5 | 15 |
| b - 3 | 3 | 1 |
| a | 0 | 10 |
| b | 6 | 4 |
Vậy các cặp số (a;b) là : (0;6) ; (10;4)
toán bằng tiếng anh nè các bạn vui lòng ghi cách giai nhe
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