I have two equations that I have to find the value of two variables within them. It also uses summation in both equation. My purpose is finding the value of $x$ and $y$. Can you help me with how to modify the equation to be like $(x = \ldots, y = \ldots)$ The complete equations are stated below: $$\sum_{k=c_i}^H (H-c_i)_{k}x^{k-c_i} y = Q_i(H)$$ and $$\sum_{k=c_i}^H (k-c_i)(H-c_i)_{k}x^{k-c_i} y= L_i(H)$$
where $(n)_k=n(n−1)...(n−k+1)$