
	 Let $a,b$ and $c$ be real numbers such that
\begin{align*}
a^2+ab+b^2&=9 \\
b^2+bc+c^2&=52 \\
c^2+ca+a^2&=49.
\end{align*}
Compute the value of $\dfrac{49b^2+39bc+9c^2}{a^2}$.

Let's think step by step and output the final answer within \boxed{}.
user