Answer:
A. -4.3 F
Step-by-step explanation:
Originally you started with 11.4 F, and the question said it decreased by 15.7 F so that basically means you subtract the final condition from initial,
11.4 F - 15.7 = -4.3 F, so at night it was -4.3 F cold.
If you think about this question in terms of apples. Originally I gave you 12 apples to keep for a day. When I returned home at 7pm the numbers of apples decreased by 8. So bascially my final apples will be 12- 8 = 4 apples remaining.
