SOLUTION
[tex]\begin{gathered} Given \\ 2h+9=21 \end{gathered}[/tex][tex]\begin{gathered} Step\text{ 1:} \\ Subtract\text{ 9 from both sides} \\ 2h+9-9=21-9 \\ 2h=12 \end{gathered}[/tex][tex]\begin{gathered} Step\text{ }2: \\ Divide\text{ both sides by 2} \\ \frac{2h}{2}=\frac{12}{2} \\ h=6 \end{gathered}[/tex][tex]\begin{gathered} Final\text{ answer:} \\ h=6 \end{gathered}[/tex]
