Simplify:

(1)/(z-4)-(1)/z+4

To simplify the expression (1)/(z-4) - (1)/(z+4), we need to find a common denominator for the two fractions. The common denominator is (z-4)(z+4), as it includes both z-4 and z+4.

Now, let's rewrite the fractions using the common denominator:

(1)/(z-4) - (1)/(z+4) = [(1)(z+4)]/[(z-4)(z+4)] - [(1)(z-4)]/[(z-4)(z+4)]

Simplifying the numerators, we get:

(z+4) - (z-4) = z + 4 - z + 4

Combining like terms, we have:

z - z + 4 + 4 = 8

Therefore, the simplified expression is 8/(z^2 - 16).