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[tex]A= 4^{n} * 3^{n+1} -2 ^{2n} * 9^{n} =\ \textgreater \ \\ =\ \textgreater \ A= 4^{n} * 3^{n}*3- 4^{n} * 3^{n}* 3^{n} =\ \textgreater \ \\ =\ \textgreater \ A= 12^{n} *3- 12^{n} * 3^{n} =\ \textgreater \ \\ A= 12^{n} (3- 3^{n} )[/tex]