Answer:
11 dimes and 16 quarters
Step-by-step explanation:
system of equations lol
It takes about 4 days for the temperature to decrease by 9°F.
An equation is an expression that shows the relationship between two or more variables or numbers.
Let x represent the number of days. Given that the temperature drop decreased by 1 1/2°F each day (- 1 1/2), for it to decrease by 9°F (-9):
-1 1/2 * x = -9
-1.5x = - 9
x = 4 days
It takes about 4 days for the temperature to decrease by 9°F.
We have the function:
()=−2(−3)^4+1
We need to go from this equation to the parent function x^4. To do that, we first do a vertical translation of 1 unit below. That is:
Vertical translation: f(x) - 1
= −2(−3)^4
Now, we make a horizontal shift of 3 units to the left, replacing x by x + 3:
f(x + 3) + 1 = −2()^4
Horizontal shift: f(x + 3) - 1
= −2x^4
We can make a horizontal expansion if we multiply this function by 1/2:
Horizontal expansion: ( f(x + 3) - 1 ) / 2
= -x^4
Finally, we make a reflection around the x-axis by multiplying this result by -1:
x-axis reflection: -( f(x + 3) - 1 ) / 2
= x^4
Let's assume that Kirby walks with a speed
for a time
, and that he runs with a speed
for a time
.
The total time available for Kirby to catch the train is:
and this must be equal to the sum of the two times t1 and t2:
The distance Kirby should cover is
and this should be equal to the sum of the distances covered by walking and by running:
So we have a system of 2 equations:
If we solve the system, we find:
So, Kirby needs to run at least for 8 minutes in order to catch the train.
Answer:
d.a cluster sampling
Step-by-step explanation:
This plan exemplifies Cluster sampling. It is a sampling method where populations are placed into different separate groups like here into freshman, sophomore, junior, and senior classes. A random sample of these groups is then selected as here thirty students selected from each group to represent a specific population.<u> It is usually used in that type of research when there is no possible way to find information about a population as a whole.</u>
