Question 413953
You're close. You're missing the 5 {{{root(3, r^3)}}}:
{{{root(3, r^17) = root(3, r^3*r^3*r^3*r^3*r^3*r^2) = root(3, r^3)*root(3, r^3)*root(3, r^3)*root(3, r^3)*root(3, r^3)*root(3, r^2) = r*r*r*r*r*root(3, r^2) =
r^5*root(3, r^2)}}}