Answer :
the equation is:
[tex](z-9)+2=9[/tex]Now we can substrac -2 in bout sides of the equation:
[tex]\begin{gathered} z-9+2-2=9-2 \\ z-9=7 \end{gathered}[/tex]now we can add 9 so:
[tex]\begin{gathered} z-9+9=7+9 \\ z=16 \end{gathered}[/tex]the equation is:
[tex](z-9)+2=9[/tex]Now we can substrac -2 in bout sides of the equation:
[tex]\begin{gathered} z-9+2-2=9-2 \\ z-9=7 \end{gathered}[/tex]now we can add 9 so:
[tex]\begin{gathered} z-9+9=7+9 \\ z=16 \end{gathered}[/tex]