Răspuns:
[tex] {3}^{n + 2} - {5}^{n} = {5}^{n + 1} - {3}^{n} [/tex]
[tex] {3}^{n + 2} + {3}^{n} = {5}^{n} + {5}^{n + 1} [/tex]
[tex] {3}^{n} ( {3}^{2} + 1) = {5}^{n} (1 + 5)[/tex]
[tex] {3}^{n} \times 10 = {5}^{n} \times 6[/tex]
[tex] {3}^{n} \times 2 \times 5 = {5}^{n} \times 2 \times 3[/tex]
n = 1
EOF = 15 × 2 = 30°
