fix a minor typo in the equation

Author: HumphreyYang

lectures/markov_jump_lq.md

@@ -203,7 +203,7 @@ $i = 1, \ldots, n$ satisfy the $N$ interrelated Bellman equations
 $$
 \begin{aligned}
 -x' P_i x - \rho_i & = \max_u -
-     x'R_i x  & + u' Q_i u + 2 u' W_i x +
+     x'R_i x + u' Q_i u + 2 u' W_i x +
              \beta \sum_j \Pi_{ij}E ((A_i x + B_i u + C_i w)' P_j
              (A_i x + B_i u + C_i w) x + \rho_j)  
 \end{aligned}