Use Desmos. It is good.
Here is the graph.
https://www.desmos.com/calculator/wq4kzps9fq
To change the color, you have to click on the line next to the formula for a long time. A window will pop up so you can change the color.
Answer:
6.66 hours, that is, 6 hours and 40 minutes.
Step-by-step explanation:
If Mike can plow a field in 12 hours, we plows 1/12 of the field each hour.
If Phil can plow a field in 15 hours, we plows 1/15 of the field each hour.
So if they are working together, they can plow (1/12) + (1/15) of the field each hour, that is:
(1/12) + (1/15) = (5 + 4) / 60 = 9 / 60 = 3 / 20 = 1 / 6.66
So if they work together, they can plow the field in 6.66 hours, that is, 6 hours and 40 minutes.
Answer: 
Step-by-step explanation:




Answer:
$21.60
Step-by-step explanation:
First, you know you have three DVDs making the total of $64.80, so to convert it to the price of one, you must divide 64.80 by three, this is to find the price of one DVD itself.