1. Stating the problem: Simplify the expression $-7s(2r)(-4r^8s^2)$ and compare it to $56r^9s^3$. 2. Use the distributive property and multiplication rules for exponents: When multiplying like bases, add the exponents. 3. Multiply the coefficients: $-7 \times 2 \times -4 = 56$. 4. Multiply the variables: $s \times r \times r^8 \times s^2 = r^{1+8} s^{1+2} = r^9 s^3$. 5. Combine the results: $$-7s(2r)(-4r^8s^2) = 56r^9s^3$$. 6. The simplified expression matches $56r^9s^3$ exactly. Therefore, the expression simplifies to $56r^9s^3$.