When adding numbers with fraction exponents do you add the exponents?

nth root (a) = a^(1/n)

mth root a^(1/m)

a^(1/n) + a^(1/m) = a^(1/n) + a^(1/m)

However. when multiplying

a^(1/n) X a^(1/m) = a^([m + n]/[mn])

Think of addition of fractions , where the exponents are concerned.

NB This can only be done when the coefficient 'a' is the same for both numbers.

NNB a^(1/n) means the 'n th root' of 'a'.