Final answer:
To find the final temperature, subtract the change in temperature from the initial temperature.
Step-by-step explanation:
The final temperature of the substance can be calculated using the formula Tfinal = Tinitial - ΔT, where Tfinal is the final temperature, Tinitial is the initial temperature, and ΔT is the change in temperature.
In this case, since the temperature of the substance decreases 7.5°C, ΔT is -7.5°C (negative because it is a decrease).
Substituting the values into the formula, we get Tfinal = Tinitial - (-7.5°C) = Tinitial + 7.5°C.
Therefore, the final temperature of the substance is higher than the initial temperature by 7.5°C.