Answer
$p=-10.4$
Work Step by Step
$\begin{align*}
-6.5-3.9&=p+3.9-3.9 &\text{Subtract 3.9 from each side of the equation.}\\
-10.4&=p &\text{Simplify.}
\end{align*}$
Thus, the solution is $p=-10.4$.
Check the solution by substituting $-10.4$ to $p$ in the original equation:
$\begin{align*}
-6.5&\stackrel{?}{=}-10.4+3.9\\
-6.5&\stackrel{\checkmark}{=}-6.5
\end{align*}$
