Question

Write $\subseteq$ or $⊈$ in each blank to make a true statement.
(a) $\{4,5,6,7\}----\{4,5,6,7,8\}$
(b) $\{a,b,c\}----\{b,e,f,g\}$

Answer 1

(a) $\{4,5,6,7\}----\{4,5,6,7,8\}$
Since every element of $\{4,5,6,7\}$ is also an element of $\{4,5,6,7,8\}$, place $\subseteq$ in the blank.
$\therefore \{4,5,6,7\}\subseteq \{4,5,6,7,8\}$
(b) The element $a$ belongs to $\{a,b,c\}$ but not to $\{b,e,f,g\}$ So, place $⊈$ in the blank
$\therefore \{a,b,c\}⊈\{b,e,f,g\}$