1. **Stating the problem:** Find the value of the expression $1 + 2 + 3 + 4 - 5^3$. 2. **Formula and rules:** - The exponentiation operation is performed before addition and subtraction. - Calculate $5^3$ which means $5 \times 5 \times 5$. - Then perform the addition and subtraction from left to right. 3. **Calculate the exponent:** $$5^3 = 5 \times 5 \times 5 = 125$$ 4. **Calculate the sum of the first four numbers:** $$1 + 2 + 3 + 4 = 10$$ 5. **Substitute and simplify:** $$10 - 125$$ 6. **Final calculation:** $$10 - 125 = -115$$ 7. **Check the options:** None of the options (a. 15, b. 10, c. 5, d. 0) match the calculated result $-115$. **Note:** The problem as stated leads to $-115$, which is not among the given choices. Possibly a typo or misunderstanding in the problem or options. **Final answer:** $-115$ (not listed in options)