\[\begin{aligned} \mathbb{N} &=\{1,2,3,\cdots\} \quad \text{(the set of }\textbf{natural numbers}\text{ or positive integers)} \\ \mathbb{Z} &=\{\cdots,-3,-2,-1,0,1,2,3,\cdots\} \quad\text{(the set of...\[\begin{aligned} \mathbb{N} &=\{1,2,3,\cdots\} \quad \text{(the set of }\textbf{natural numbers}\text{ or positive integers)} \\ \mathbb{Z} &=\{\cdots,-3,-2,-1,0,1,2,3,\cdots\} \quad\text{(the set of }\textbf{integers}) \\ \mathbb{Q} &=\left\{ \frac{n}{m} \mid n,m\in\mathbb{Z}\text{ and }m\neq 0\right\} \quad \text{(the set of }\textbf{rational numbers}) \\ \mathbb{R} &=\text{the set of }\textbf{real numbers}\\ \mathbb{C} &= \left\{a+bi \mid a,b \in \mathbb{R} \right\} \quad \text{(the set of …
If \(a\) divides \(b\), we write \(a \mid b\), and we may say that \(a\) is a divisor of \(b\), or that \(b\) is a multiple of \(a\), or that \(b\) is a divisible of \(a\). For example, \(a \mid a\) b...If \(a\) divides \(b\), we write \(a \mid b\), and we may say that \(a\) is a divisor of \(b\), or that \(b\) is a multiple of \(a\), or that \(b\) is a divisible of \(a\). For example, \(a \mid a\) because we can write \(a \cdot 1= a\); \(1 \mid a\) because we can write \(1 \cdot a= a\); \(a \mid 0\) because we can write \(a \cdot 0= 0\).
