Your picture has several issues.
- x is not defined. It appears to be the number of apartments rented.
- R(x) is defined two different ways. The first way, it looks like it is the revenue from a single apartment. The second way, it looks like it is the revenue from the entire apartment complex.
- The derivative is in error. It should be -20x +2000. In any event, this is not the derivative you want. You're not trying to maximize revenue; you're trying to maximize profit.
- It might be useful to write an equation for profit: P(x) = R(x) -200x = -10x² +1800x. Then when you go to maximize it, your derivative will be P'(x) = 0 = -20x +1800 ⇒ x = 90.
Your answer is correct, but the path you followed to get there has a few potholes.
Answer:
80% or 4/5
Step-by-step explanation:
There are five numbers and four of the numbers are positive which means you'll have 4 out of 5 chance getting a positive number, which is equivalent to 80%
Answer:
The total area (including the area of the circle) would be 16 × 16 = 256 square centimetres.
The area of the circle would be (taking the value of pi as 3.14) is 200.96 square centimetres
The area of the shaded region would be 256 - 200. 96 = 55.04 square centimetres
Answer: Leanna ran 39.96 miles before she was passed by Irina.
Step-by-step explanation:
When Irina would pass Leanna, they would have ran the same distance.
Let t represent the time that Leanna ran before she was passed by Irina.
Distance = speed × time
Leanna started in group E and ran at a rate of 4.8 miles per hour. The distance ran by Leanna before she was passed by Irina is
4.8 × t = 4.8t
During the race she was passed by Irina who ran at a rate of 5 miles per hour and started in group H, 20 minutes(20/60 = 0.333 hour) after Leanna started. The time spent by Irina in running this distance is
t - 0.333
Distance ran by Irina is
5(t - 0.333) = 5t - 1.665
Since they ran the same distance, then
4.8t = 5t - 1.665
5t - 4.8t = 1.665
0.2t = 1.665
t = 1.665/0.2 = 8.325 hours
Therefore, the distance that Leanna ran before she was passed by Irina is
4.8 × 8.325 = 39.96 miles
