Answer:
I need more information.
Step-by-step explanation:
I like A as the best one
420 = 100*price - (fixed costs)
220 = 60*price - (fixed costs)
If we subtract one from the other one, we get 200 = 40*price, price = 5
that said, fixed costs are 500 - 420 = 80
Now if we move -220 to the right in Answer A, we'll get:
y = 5x -300 + 220 = 5x - 80
So it looks like A describes the model best
The key is Esther travelled the same distance - x - in both her morning and evening commute.
45(time she took in the morning, or p) = x
30(time she took in the evening, or q) = x
Therefore 45(p) = 30(q), or divide both sides by 5 and get 9(p) = 6(q). I know you can divide it further, but these numbers are small enough and it's not worth the time.
Since the whole trip took an hour, (p + q) = 60min, and so, p = 60-q.
Therefore 9(60-q) = 6q or 540-9q = 6q. So 540 = 15q, which makes q = 36. If q = 36, then by (p+q)=60, p (the time she took in the morning) must equal 24.
45 miles per hour, her speed in the morning, times (24/60) hours, her time, makes 18 miles travelled in the morning. If you check, 30 miles per hour times (36/60) hours also makes 18 miles in the evening.
<span>Hope that makes a little sense. And I also hope it's right</span>
It is already in identity.
cos (x - y) - cos (x + y) = 2 sin(x) sin (y)