Given positive real values $j, k$ and $l$ such that $\begin{array}{l l} j^2 +k^2 + jk & = & 9 \\ k^2 + l^2 + kl & = & 16\\ l^2 + j^2 + lj & = & 25,\\ \end{array}$ $(j + k + l)^2$ has the form $a + b \sqrt{c}$, where $a, b$ and $c$ are integers and $c$ is not a multiple of any square number. What is $a + b + c$?