Answer: 
Step-by-step explanation:
Sine uses the ratio,
so we can plug in the information we know. since there is no current value for the opposite side of angle A, we can just use a variable to replace it.

You can't reduce this any further because there is an unknown variable.
Answer:
You would have 4 red marbles and 8 blue marbles since you didn't return the ones you took out to the bag.
Step-by-step explanation:
6 - 2 = 4
The 8 would stay the same
There for you would have 4 red marbles and 8 blue marbles left in the bag. Totalled you have 12 marbles in the bag and 2 out of the bag. (8 + 4 = 12)
Including the marbles in and out of the bag you have 14 marbles. The 12 inside the bag + the 2 outside of the bag = 14 marbles totalled.
47 - 19 = 28
28/4 = 7
At most they can spend 7 hours
The solution is
T = (47-19)/4
T = 28/4
T = 7
I think that solution is what your teacher is asking for, i'm not certain but ik the answer should be 7 hours.