Question

Write the given set in roster form

$J=\left\{x|x\in N,7x>21\right\}$

Answer 1

Roster form-When the elements are represented by listing all its elements (without repetition) separating them by commas and enclosing them within curly brackets.

$$\begin{gathered} \Rightarrow 7x>21 \\ \Rightarrow x>3. \end{gathered}$$ Hence Set $J=\{4,5,6,......\}$