Answer:
3.7s8t + 7.1
To distribute the "-" sign outside the parentheses in the expression -(-3.7s8t) - 7.1, we first apply the negative sign to the term inside the parentheses, which is -(-3.7s8t) = 3.7s8t. Then we add the 7.1 to the 3.7s8t, giving us the final expression 3.7s8t + 7.1.