Answer:
[tex]a_{n}=5\times \left( 7\right)^{n-1}[/tex]
Step-by-step explanation:
[tex]a_{n}=a_{n-1}\times7[/tex]
Then the common ratio = 7
Then the explicit formula is :
[tex]a_{n}=a_{1}\times \left( 7\right)^{n-1}[/tex]
[tex]=5\times \left( 7\right)^{n-1}[/tex]