1.6
$ log_{3}x = 1 + log_{x}3^{2}$
$ log_{3}x = 1 + 2log_{x}3$
$ log_{3}x = 1 + \frac{2}{log_{x}3}$
Let $ log_{3}x = A$
$ A = 1 + \frac{2}{A}$
$ A^{2} = A + 2 $
$ A^{2} - A - 2 $
$(A-2)(A+1) = 0, A = 2, -1$
$ log_{3}x = 2, -1$
$x = 3^{2}, 3^{-1}$
1.7 ทำนองเดียวกัน
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