Need help with 13, 14, and 15. Please, and thank you. :))

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap