(13) the temperature on a cold winter day is 2 degrees below zero. in the night, the temperature drops an additional 14 degrees. express the nighttime temperature as an integer. *
16 degrees
12 degrees
-16 degrees,
(14) write the difference 30 – (–12) as a sum, then simplify. *
30 - 12 = 18
30 + 12 = 18
30 + 12 = 42

Well, in the first one, 2 degrees below zero is -2 degrees, and then it says that it dropped 14 degrees, which means it dropped -14 degrees, so to know the total amount it dropped you would just have to add -2 plus -14 which is -16 degrees, so your answer for the first question would be the last answer, -16 degrees.

For the second question, just know that whenever a negative number is BY ITSELF in parentheses, that means it is used like a positive number in the equation. So (-12) automatically becomes 12. Now, since the problem is asking for a SUM, (the answer to an ADDITION problem; when you add instead of subtract), you would turn that minus symbol to a plus symbol, and add normally to get your final answer; 30 + 12 = 42. To check if this is correct, just type in 30 – (–12) to a calculator and you'll get the same answer! :D
Hope this helps! :3