Exercițiul 5 (a)
[tex] {2}^{n} \times {5}^{n - 1} = 2000[/tex]
[tex] {2}^{n} \times {5}^{n} \times {5}^{ - 1} = 2000[/tex]
[tex] {2}^{n} \times {5}^{n} \times \frac{1}{5} = 2000[/tex]
[tex] {(2 \times 5)}^{n} \times \frac{1}{5} = 2000 [/tex]
[tex] {10}^{n} \times \frac{1}{5} = 2000[/tex]
[tex] {10}^{n } = 10000[/tex]
[tex] {10}^{n} = {10}^{4} [/tex]
[tex]n = 4[/tex]
