Calculate 1 - ((1)/(30) + (1)/(15))

To add the fractions $\frac{1}{30}$ and $\frac{1}{15}$, find a common denominator. The least common multiple of 30 and 15 is 30.

$$\frac{1}{30} + \frac{1}{15} = \frac{1}{30} + \frac{1 \times 2}{15 \times 2} = \frac{1}{30} + \frac{2}{30}$$

$$1 - \frac{1}{10}$$

To subtract, express 1 as a fraction with a denominator of 10:

$$\frac{10}{10} - \frac{1}{10} = \frac{10-1}{10} = \frac{9}{10}$$

The final answer is $\frac{9}{10}$.