Question

Let $A=\{a,e,i,o,u\}$ and $B=\{a,i,u\}$. Show that $A\cup B=A$

Answer 1

Given: $A=\{a,e,i,o,u\}$ and $B=\{a,i,u\}$
$\therefore A\cup B=\{a,e,i,o,u\}\cup \{a,i,u\}$
$=\{a,e,i,o,u\}$
$A\cup B=A$
Hence proved.