[tex]b)~3^{2n+3}=3^{21}:3^{6} \\ \\ 3^{2n+3}=3^{15} \\ \\ 2n+3=15 \\ \\ n=6[/tex]
[tex]c)~5^{3n+1}=5^{22} \\ \\ 3n+1=22 \\ \\ n=7[/tex]
[tex]d)~7^{n+1}:7^4=49^8 \\ \\ 7^{n+1}:7^4=7^{16} \\ \\ 7^{n+1}=7^{20} \\ \\ n+1=20 \\ \\ n=19[/tex]
La e nu se inteleg bine exponentii
