Question

3^n+1 + 3^n = 36 x 3^15

Answer 1

${3}^{n + 1} + {3}^{n} = 36 \times {3}^{15} \\ \\ (3 + 1) \times {3}^{n} = 36 \times {3}^{15} \\ \\ 4 \times {3}^{n} = 36 \times {3}^{15} \\ \\ {3}^{n} = 9 \times {3}^{15} \\ \\ {3}^{n} = {3}^{17} \\ \\ = > n = 17$