Answer:30° - 3d ≤ 20°
Step-by-step explanation:
We have to represent the rate of temperature decrease in degrees .We will represent this by "d" which stands for degree.
According to the question , temperature decreased at a constant rate in the next three days
Therefore , the total decreasing in three days = 3d degree i.e 3 *d=3d
Temperature on Monday = 30°
Then the temperature on Thursday is this = 30° - 3d
Since, The swimming pool is open when the high temperature is higher than 20°=≤20
= 30° - 3d ≤ 20°
This is the required inequality to determine the rate of temperature decrease in degrees Celsius per day, "d"from Monday to Thursday.
