Answer: False
Reason:
It should be a^(-3)*a^(-3)=a^(-6) based on the rule a^b*a^c = a^(b+c)
A way to see why the equation a^(-3)+a^(-3)=a^(-6) is false is to pick a number like a = 1 to find that...
a^(-3)+a^(-3)=a^(-6)
1^(-3)+1^(-3)=1^(-6)
1/(1^3) + 1/(1^3) = 1/(1^6)
1/1 + 1/1 = 1/1
1+1 = 1
2 = 1
Which is false, so this shows the original equation is false for a = 1. Therefore it is false in general.