Question 394970
Basically they are asking you to solve for I in the problem above.
{{{S=2sqrt(I-5)}}}  
{{{S/2=sqrt(I-5)}}} 
{{{(S/2)^2=I-5}}}
{{{(S/2)^2-5=I}}}
{{{I=S^2/4-5}}}

If my steps were not clear enough, let me know and I can post clearer steps on solving for "I".

Anyway, from here, just need to plug in the 17 for S, and then solve for I.
You answer ends up being 67.25.

Hope this helps,
J