Răspuns
Explicație pas cu pas:
17^n + 17^n+1 = 17^n (1 + 17) = 18 * 17^n
7^n + 7^n+1 = 7^n (1 + 7) = 8 * 7^n
18 * 17^n / 8 * 7^n = 9*17^n / 4*7^n
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36*6^n - 2^n+2*3^n+1 - 2^n+1*3^n+2 = 36*2^n*3^n - 2^n+2*3^n+1 - 2^n+1*3^n+2 = 2^n*3^n (36 - 4*3 - 2*9) = 2^n*3^n (36 - 12 - 18) = 6*6^n = 6^n+1
36*6^n - 6*6^n - 21*6^n = 6^n(36 - 6 - 21) = 9*6^n
6^n+1 / 9*6^n = 6/9 = 2/3
