[tex]a(n) = 6 + 3(n - 1)[/tex]
[tex]a(1) = 6 + 3(1 - 1)[/tex]
[tex]a(1) = 6 + 3 \times 0[/tex]
[tex]a(1) = 6 + 0[/tex]
[tex]a(1) = 6[/tex]
_________________________________
[tex]a(2) = 6 + 3(2 - 1)[/tex]
[tex]a(2) = 6 + 3 \times 1[/tex]
[tex]a(2) = 6 + 3 [/tex]
[tex]a(2) = 9[/tex]
_________________________________
[tex]a(3) = 6 + 3(3 - 1)[/tex]
[tex]a(3) = 6 + 3 \times 2[/tex]
[tex]a(3) = 6 + 6[/tex]
[tex]a(3) = 12[/tex]
_________________________________
[tex]a(4) = 6 + 3(4 - 1)[/tex]
[tex]a(4) = 6 + 3 \times 3[/tex]
[tex]a(4) = 6 + 9[/tex]
[tex]a(4) = 15[/tex]
