Question

Write an equation for the nth term of the arithmetic sequence.

Answer 1

Answer:

             $\bold{a_n=6n-3}\\\\\bold{a_{50}=297}$

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:

                         $a_n=a+d(n-1)\\\\a_n=69+6(n-1)\\\\a_n =3+6n-6\\\\\underline{a_n=6n-3}$                        

and:

   $a_{50}=6\cdot50-3=300-3=297$