To eliminate the i in the denominator, you multiply it by (6+5i), because (a+b)(a-b)=a²-b², we need i² to eliminate i. Recall that i²=-1
-1(6+5i)/(6-5i)(6+5i)=(-6-5i)/[6²-(5i)²]=(-6-5i)/(36-25i²)=(-6-5i)/61
your choices are all correct. You need to check the 7th answer as well.
