Find all excluded values for the expression. That is, find all values of \( y \) for which the expression is undefined. \( \frac{y-5}{y^{2}-64} \) If there is more than one value, separate them with commas.

To find the excluded values for the expression \( \frac{y-5}{y^{2}-64} \), we need to identify when the denominator is equal to zero, as division by zero is undefined. The denominator is \( y^{2} - 64 \). We can factor this difference of squares: \[ y^{2} - 64 = (y - 8)(y + 8) \] Setting the denominator equal to zero gives us: \[ (y - 8)(y + 8) = 0 \] From here, we can solve for \( y \): 1. \( y - 8 = 0 \) leads to \( y = 8 \) 2. \( y + 8 = 0 \) leads to \( y = -8 \) Thus, the excluded values for the expression are \( y = 8, -8 \).