SOLUTION
[tex]\begin{gathered} A=[6,\infty) \\ B=(8,\infty) \\ A\cup B=? \end{gathered}[/tex][tex]\begin{gathered} A=\lbrace6,7,8,9,10,...\rbrace \\ B=\lbrace9,10,...\rbrace \\ A\cup B=\lbrace6,7,8,9,10,...\rbrace \\ A\cup B=[6,\infty) \end{gathered}[/tex]
