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I have a problem wiyh this formula,

i need to write this formulation on more than 1 line, the problem is tat the last \right], don't appear in pdf file... i don't know why...

the script is that:
\documentclass[a4paper, 11pt]{book}
\usepackage{amsmath, amssymb, amsfonts, amsthm}

\begin{equation ...