Final answer:
The mathematical sentence that expresses the given information is: t + 8 ≥ 82.
Step-by-step explanation:
To express the given information mathematically, we can write the equation t + 8 ≥ 82. This equation states that if the temperature, represented by the variable t, rises by 8 degrees, it will be greater than or equal to the record high temperature of 82 degrees.