Can you tell me how you went from 3^203 to 3^3 in the last line? Then I know 3^3 is 27 and then how did you get 5 from there? I understand the mod(11) part. Thanks!
Okay, = is supposed to mean 'congruent to' instead of 'equals'.
I multiplied both sides by 3^3. And then 3^3=27 and under mod 11 that is 5.