Chapter 7 - Exponents and Exponential Functions - 7-2 Multiplying Powers With the Same Base - Practice and Problem-Solving Exercises - Page 429: 16

$8t^{-8}$= $8/t^8$

When we multiply two numbers with different exponents but the same base, we raise the base to the power of the two exponents added together. Thus, we know that t should be raised to the power of (-3)+(-5), which equals -8. We also multiply the coefficients, 4 and 2, to get the new coefficient, 8. Thus, our answer is: $8t^{-8}$. Because we have a negative exponent, this can be rewritten as: $8/t^8$.