In the equation

, a is the initial amount and b is the growth factor. So our initial amount is 30 and our growth factor is 8.3. Your correct choice for this is A.
The answer is 18, the answer is always just the number in the brackets( hope this helps)
Answer:
31-19=12°F
12°F
Step-by-step explanation
If it was 19 degrees on Monday and 31 degrees on Tuesday you have to see how much did it go up in temp. So..
the difference between 19 and 31 is 12, so that means it went up by 12°F.
It would be the last option, (5, -4)