[tex]A= \left[\begin{array}{ccc}a_{11}&a_{12}\\a_{21}&a_{22}\\a_{31}&a_{32}\end{array}\right] \\
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A= \left[\begin{array}{ccc}{1+2.1}&{1+2.2}\\{2+2.1}&{2+2.2}\\{3+2.1}&{3+2.2}\end{array}\right] \\
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A= \left[\begin{array}{ccc}{3}&{5}\\{4}&{6}\\{5}&{7}\end{array}\right] [/tex]
