How do you find w(3n) given w(n)=4n+2?

$w \left(3 n\right) = 12 n + 2$
$\text{to evaluate "w(3n)" substitute "n=3n" into } w \left(n\right)$
$\Rightarrow w \left(\textcolor{red}{3 n}\right) = 4 \left(\textcolor{red}{3 n}\right) + 2 = 12 n + 2$