###### Example 2.4.2 A Solution

Consider the equation \(y+2=3\text{,}\) which has only one variable, \(y\text{.}\) If we substitute in \(1\) for \(y\) and then simplify:

\begin{align*}
y+2\amp=3\\
\substitute{1}+2\amp\stackrel{?}{=}3\\
3\amp\stackrel{\checkmark}{=}3
\end{align*}

we get a true equation. So we say that \(1\) is a solution to \(y+2=3\text{.}\) Notice that we used a question mark at first because we are unsure if the equation is true or false until the end.