[tex]\begin{gathered} 5+5=10 \\ _{\text{ }}and \\ 5+5+n=10+n \end{gathered}[/tex]
The equations are equivalent by the equality property of addition, which states that if we add the same quantity to both sides of an equation, then our equation remains the same. Since john is adding n to both sides, the equation remains the same and therefore, they are equivalent.
