Question

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4 задание пожалуйста

Answer 1

Ответ: 1

$\displaystyle 9 {}^{n} - 2 \times {3}^{n} - 3 = 0 \\ ( {3}^{n} ) {}^{2} - 2 \times {3}^{n} - 3 = 0 \\ zamena \: 3 {}^{n} = t \\ t {}^{2} - 2t - 3 = 0 \\ t1 \times t2 = - 3 \\ t1 + t2 = 2 \\ t1 = 3 \: t2 = - 1 \\ {3}^{n} = 3 \\ n = log_{3}(3) = 1 \\ {3}^{n} = - 1 \\ n = log_{3}( - 1) net \: korney \\ otvet \: n = 1$