1. The problem is to simplify the fraction $\frac{7}{15}$ or understand why it might "not be working" in a certain context. 2. The formula for simplifying fractions is to divide the numerator and denominator by their greatest common divisor (GCD). 3. Find the GCD of 7 and 15. Since 7 is a prime number and does not divide 15, the GCD is 1. 4. Simplify the fraction by dividing numerator and denominator by 1: $$\frac{\cancel{7}}{\cancel{15}} = \frac{7}{15}$$ 5. Since the fraction cannot be simplified further, $\frac{7}{15}$ is already in its simplest form. 6. If "not working" refers to a calculation or usage, ensure the fraction is correctly input or used in the problem context. Final answer: $\frac{7}{15}$