Diketahui 7^2x+3 = 1/343. Nilai x dipenuhi oleh...

[tex] 7^{2x+3} = \frac{1}{343} \\ 7^{2x+3} = 7^{-3} \\ 2x + 3 = -3 \\ 2x = -3 - 3 \\ 2x = -6 \\ x = \frac{-6}{2} \\ x = 3 [/tex]