1)(-√6+√6i)/(5-6i)=(-√6+√6i)(5+6i)/(5-6i)(5+6i)=(-5√6-6√6i+5√6i-6√6)/(25+36)=
=(-11√6-√6i)/61
2)[(5-6i)²-3]/[(-√6+√6i)(-√6-√6i)+(5-6i)]=(25-60i-36-3)/(6+6+5-6i)=
=(-14-60i)/(17-6i)=(-14-60i)(17+6i)/(289+36)=(-238-84i-1020i+360)/325=
=(122-1104i)/325
3)(z2)³(-√6-√6i)³=-6√6-18√6i+18√6+6√6i=12√6-12√6i
(z2)^6=(12√6-12√√6i)²=144*6-2*144*6i-144*6=-1728i