So y+x=2
x-y=4
one way is subsituteion where yousubisutte one of the number for another exg
x-y=4
add y to both sides
x=y+4
subsitute y+4 for x in x+y=2
y+4+y=2
2y+4=2
subtract 4 from both sides
2y=-2
divide both sides by 2
y=-1
subsiutte
x+y=2
x-1=2
x=3
or elimination
x+y=2
x-y=4
add the two equations and cancel the y terms
x+x+y-y=2+4
2x=6
divide both sides by 2
x==3
subsitute
x+y=2
3+y=2
y=-1
so x=3
y=-1
Answer: the answer i got is the 30
Step-by-step explanation:
so first you had to do the parentheses
(5-2)=3
[4+6 multiplied by 3] + 8
[4+18]+8
22+8
=30
Answer:
--- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
<u>Start by calculating the mean</u>
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.

So, we have:



Next, calculate the variance using the following formula:

i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:



Lastly, take the square root of the variance to get the standard deviation


--- approximated
<em>Hence, the standard deviation is approximately 11.28</em>
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
Answer: a) 2092278989 b) 576, c) 
Step-by-step explanation:
Since we have given that
Number of students = 16
Number of desks = 16
a) How many days must pass before the class must repeat a seating arrangement?

If the number of rows = 4
b) How many seating arrangements are there that put Larry, Moe, Curly, and Shemp in the front seats?

c) How many seating arrangements are there that put Larry, Moe, Curly, and Shemp in the front seats?

Hence, a) 2092278989 b) 576, c) 