Answer:
The expression is (-24) / 6 = -4degrees which means that in each week the average change in temperature was -4 degrees Celsius.
Step-by-step explanation:
Change in a quantities can as well be interpreted as rate of change which is used in many everyday problems, such as weather forecast, traveling , in science and so on.When we are talking about rate of change it's is usually in ratio such as Miles per hour or feet per second can be used in calculation involving rates of speed. It is how one quality is changing with respect to time , for instance, rate equals distance divided by time: r = d/t.
In finance rate of change is also applicable we can have Unit price which is a particular rate that compares a price to some unit of measure. Example is $64 per dozen.
Therefore, Given from the question,
The temperature of a city changed -24 degrees Celsius ,
Time =6 weeks period.
Then change is r = d/t.
= (-24) / 6
Change = (-24) / 6 = -4 degrees
This means that each week the average change in temperature was -4 degrees Celsius.
Answer: 16590
Step-by-step explanation:
The formula we use to find the sample size is given by :-
, where p = prior estimate of population proportion.
= Critical z-value (Two- tailed)
E= Margin of error .
Let p be the population proportion of cyanobacteria.
Given : E = 0.01
Critical value for 99% confidence interval : 
If Ian does not want to rely on previous knowledge , then we assume p=0.5 because the largest standard error is at p=0.5.
Now, the required sample size = 

Required sample size = 16590
Answer:
18-r
Difference is subtraction.
Answer:
B.
Step-by-step explanation:
y = x^2 - x - 12
y = (x-4)×(x+3) that means x it either 4 or -3
y = x + 3
for x = 4 ➡ y = 3+4 ➡7
for x = -3 ➡ y = -3 + 3➡0
(the answer key is most probably faulty there's no way for y to be 0 in both scenarios)
It has 0 solution there are no meeting points of the two given lines.