Answer:
Cluster sample
Step-by-step explanation:
This is an example of a cluster sample. In a cluster sample, the examiner divides the population into groups (each one of these groups is called a cluster) and once the examiner has these clusters, takes one of them and recollects the data from ALL the members of that cluster. In this case, the teacher divided the class in 3 different groups and then selects one of these groups and asks the average amount of time per week he/she spent studying.
The amount of balls in a given layer can be found by squaring the layer it is in
4 layers
top layer (1st) is 1
2nd is 4
3rd layer is 9
4th is 16
add them up
1+4+9+16=30
30 in that pyramid
2(2)+7-3(2)=
4+7-6= 5
your answer is 5
Answer:
34.98+51.02+51.22= 137.22 as a positive number. 5.23+10.22+7.89= 23.34 Then 137.22-23.34= 113.88
So the negative number will be -23.34
Step-by-step explanation:
Hello there!
Let's use foil.
First: 4x * 2x = 8x^2
Outside: 4x * -9 = -36x
Inside: -7 * 2x = -14x
Last: -7 * -9 = 63
Now, let's combine these.
8x^2 - 36x - 14x + 63
Finally, we can simplify this
8x - 50x + 63
I hope I helped!
Let me know if you need anything else!
~ Zoe
