Calculati:
a)13⁵:13³+{(17³)⁵:17¹⁴+2*[(2³*5²)⁴:100⁴+253:23]}=
b)41⁶:(41³)²+53⁷:(53²)³+11*[6⁶⁶:(6¹¹):(6⁹)⁶-2¹⁴⁵:2¹² ²]=
c)81⁵:3¹⁹+31¹⁰*31⁴:31¹³+156-792:72+[(15⁶)⁴:3²³]:5²²=​