1. **State the problem:** Calculate the value of the expression $-8 \times (-10) - 7 \times \left(\frac{1}{-1}\right)$. 2. **Recall the rules:** Multiplying two negative numbers results in a positive number. Dividing by a negative number changes the sign of the result. 3. **Calculate each part:** - First part: $-8 \times (-10) = 80$ because negative times negative is positive. - Second part: $7 \times \left(\frac{1}{-1}\right) = 7 \times (-1) = -7$. 4. **Combine the results:** $$80 - (-7) = 80 + 7 = 87$$ 5. **Final answer:** The value of the expression is $87$.