all the terms are 3 less than its preceding term, simple!
So, the formula would be:
[tex]a_n=a+(n-1)d[/tex]Where
a is the first term
d is the common difference (diff in 2 terms)
From the sequnce,
first term (a) is 50
common difference (d) = 47 - 50 = -3
So, we have:
[tex]\begin{gathered} a_n=a+(n-1)d \\ a_n=50+(n-1)(-3_{}) \\ a_n=50-3n+3 \\ a_n=53-3n \end{gathered}[/tex]Explicit Formula:
[tex]a_n=53-3n[/tex]