y = 12
Explanation:[tex]12\text{ = 24 - y}[/tex]We would collect like terms by subtracting 24 from both sides:
[tex]12\text{ - 24= 24 - 24 - y}[/tex][tex]\begin{gathered} -12\text{ = 0 - y} \\ -12=\text{ -y} \end{gathered}[/tex][tex]\begin{gathered} \text{divide both sides by -1:} \\ \frac{-12}{-1}=\frac{-y}{-1} \\ y\text{ = 12} \end{gathered}[/tex]