\documentclass{book}
\usepackage{amsthm,amssymb,amsmath}
\begin{document}
\begin{eqnarray}
  ‎‏‏‎‎‏‎‎‎‎[‎\dot{P}(t)+P(t)A+A^TP(t)-P(t)ZP(t)+Q‎]x^{(k)}(t)‎‎‏‏‎‎
  &&+[‎\dot{g}^{(k)}(t)+(A^T-P(t)Zg^{(k)}(t))-P(t)N\lambda^{(k-1)}(t+\tau)‎
  &&-p(t)T\lambda^{(k-1)}(t-\tau)+P(t)f(x^{(k-1)}(t))+f_x(x^{(k-1)(t)})\lambda^{(k-1)}(t)‎]&‎‏‎‎=&‎0‎
 \end{eqnarray}‎
\end{document}