Simplify. \( \frac{10-4^{2}}{7^{2}+3^{2}} \)

First, let’s simplify the expression step by step. First, calculate \(4^{2}\) and \(7^{2}\) and \(3^{2}\): \[ 4^{2} = 16, \quad 7^{2} = 49, \quad 3^{2} = 9. \] Now, substitute these values back into the expression: \[ \frac{10 - 16}{49 + 9}. \] This simplifies to: \[ \frac{10 - 16}{49 + 9} = \frac{-6}{58}. \] Now, we can further simplify \(\frac{-6}{58}\) by finding the greatest common divisor, which is 2: \[ \frac{-6 \div 2}{58 \div 2} = \frac{-3}{29}. \] Thus, the simplified form of the expression is: \[ \frac{-3}{29}. \]