Answer: 
Step-by-step explanation:

Remove all those parentheses by multiplying. Note: 2 and 2 cancel out.

Subtract 2x

Combine like terms;

Divide by -3

Rewriting it;

Answer:
A. T = 20°C - (2.8°C/h × 4h)
Step-by-step explanation:
The rate of change of temperature (-2.8°C/h) is multiplied by time (4h) to get the change in temperature (-11.2°C). That change is added to the initial temperature (20°C) to find the temperature after 4 hours.
Only equation A properly expresses this calculation.
In choice B, the rate of change is (wrongly) shown as +2.8°C/h. In the other choices, the combinations of units are nonsense. (What is a °C·h?)
Answer:
B. $ 320
Step-by-step explanation:
[8(3) + 4(2)]10
(24 + 8)10
320