We are given the following information: At 7:00 a.m., the temperature was -3°F. At 6:00 p.m., the temperature was 9°F greater than the temperature at 7:00 a.m. This means the temperature at 6:00 p.m. is calculated as -3 + 9.
We know this last temperature is 4°F less than the temperature at noon, thus the temperature at noon is calculated as -3 + 9 + 4
