1. **State the problem:** Calculate $$\frac{13!}{720} - 89^3 + \sqrt{473926185} - 18294637$$. 2. **Recall factorial and exponentiation:** - Factorial: $$13! = 13 \times 12 \times \cdots \times 1$$. - Exponentiation: $$89^3 = 89 \times 89 \times 89$$. - Square root: $$\sqrt{473926185}$$ is the positive number which squared equals 473926185. 3. **Calculate each part:** - Calculate $$13!$$: $$13! = 6227020800$$. - Divide by 720: $$\frac{13!}{720} = \frac{6227020800}{720} = 8645860$$. - Calculate $$89^3$$: $$89^3 = 89 \times 89 \times 89 = 704969$$. - Calculate $$\sqrt{473926185}$$: Approximate $$\sqrt{473926185} \approx 21772.5$$ (rounded to one decimal). 4. **Substitute values and simplify:** $$8645860 - 704969 + 21772.5 - 18294637$$ 5. **Perform operations step-by-step:** - $$8645860 - 704969 = 7940891$$ - $$7940891 + 21772.5 = 7962663.5$$ - $$7962663.5 - 18294637 = -10331973.5$$ 6. **Final answer:** $$-10331973.5$$