Answer:
[tex]\bold{a_n=6n-3}\\\\\bold{a_{50}=297}[/tex]
Step-by-step explanation:
3, 9, 15, 21, ...
9-3 = 6; 15-9 = 6; 21-15 = 6 ⇒ d = 6
first term: a = 3
difference: d = 6
so the formula:
[tex]a_n=a+d(n-1)\\\\a_n=69+6(n-1)\\\\a_n =3+6n-6\\\\\underline{a_n=6n-3}[/tex]
and:
[tex]a_{50}=6\cdot50-3=300-3=297[/tex]
