Answer:
![13.\ (x,y) = (-4,3)](https://tex.z-dn.net/?f=13.%5C%20%28x%2Cy%29%20%3D%20%28-4%2C3%29)
![14.\ No\ Solution](https://tex.z-dn.net/?f=14.%5C%20No%5C%20Solution)
![15.\ (x,y) = (-12,-32)](https://tex.z-dn.net/?f=15.%5C%20%28x%2Cy%29%20%3D%20%28-12%2C-32%29)
![16.\ (x,y) = (3.75,6.25)](https://tex.z-dn.net/?f=16.%5C%20%28x%2Cy%29%20%3D%20%283.75%2C6.25%29)
![17.\ No\ Solution](https://tex.z-dn.net/?f=17.%5C%20No%5C%20Solution)
Explanation:
13)
---- (1)
------ (2)
Multiply equation by 5 and equation 2 by 4
![5 * 4x + 5 * 8y = 5 * 8\\4*5x + 4*7y = 4 *1](https://tex.z-dn.net/?f=5%20%2A%204x%20%2B%205%20%2A%208y%20%3D%205%20%2A%208%5C%5C4%2A5x%20%2B%204%2A7y%20%3D%204%20%2A1)
------ (3)
------ (4)
Subtract equation 3 from 4
![(20x + 28y = 4) - (20x + 40y = 40)](https://tex.z-dn.net/?f=%2820x%20%2B%2028y%20%3D%204%29%20-%20%2820x%20%2B%2040y%20%3D%2040%29)
![20x - 20x+ 28y -40y= 4-40](https://tex.z-dn.net/?f=20x%20-%2020x%2B%2028y%20-40y%3D%204-40)
![-12y = -36](https://tex.z-dn.net/?f=-12y%20%3D%20-36)
Divide both sides by -12
![\frac{-12y}{-12} = \frac{-36}{-12}](https://tex.z-dn.net/?f=%5Cfrac%7B-12y%7D%7B-12%7D%20%3D%20%5Cfrac%7B-36%7D%7B-12%7D)
![y = 3](https://tex.z-dn.net/?f=y%20%3D%203)
Substitute
in equation 1
![4x + 8(3) = 8](https://tex.z-dn.net/?f=4x%20%2B%208%283%29%20%3D%208)
![4x + 24 = 8](https://tex.z-dn.net/?f=4x%20%2B%2024%20%3D%208)
Subtract 24 from both sides
![4x + 24 - 24 = 8 - 24](https://tex.z-dn.net/?f=4x%20%2B%2024%20-%2024%20%3D%208%20-%2024)
![4x = -16](https://tex.z-dn.net/?f=4x%20%3D%20-16)
Divide both sides by 4
![\frac{4x}{4} = \frac{-16}{4}](https://tex.z-dn.net/?f=%5Cfrac%7B4x%7D%7B4%7D%20%3D%20%5Cfrac%7B-16%7D%7B4%7D)
![x = -4](https://tex.z-dn.net/?f=x%20%3D%20-4)
![Hence\ (x,y) = (-4,3)](https://tex.z-dn.net/?f=Hence%5C%20%28x%2Cy%29%20%3D%20%28-4%2C3%29)
----------------------------------------------
14)
---- (1)
----- (2)
Make x the subject of formula in (2)
![5x + 5y = 10](https://tex.z-dn.net/?f=5x%20%2B%205y%20%3D%2010)
![5x + 5y - 5y = 10 - 5y](https://tex.z-dn.net/?f=5x%20%2B%205y%20-%205y%20%3D%2010%20-%205y)
![5x = 10 - 5y](https://tex.z-dn.net/?f=5x%20%3D%2010%20-%205y)
![\frac{5x}{5} = \frac{10 - 5y}{5}](https://tex.z-dn.net/?f=%5Cfrac%7B5x%7D%7B5%7D%20%3D%20%5Cfrac%7B10%20-%205y%7D%7B5%7D)
![x = \frac{10}{5} - \frac{5y}{5}](https://tex.z-dn.net/?f=x%20%3D%20%5Cfrac%7B10%7D%7B5%7D%20-%20%5Cfrac%7B5y%7D%7B5%7D)
![x = 2 - y](https://tex.z-dn.net/?f=x%20%3D%202%20-%20y)
Substitute
in (1)
![7x + 7y = 8](https://tex.z-dn.net/?f=7x%20%2B%207y%20%3D%208)
![7(2-y) + 7y = 8](https://tex.z-dn.net/?f=7%282-y%29%20%2B%207y%20%3D%208)
Open bracket
![7*2-7*y + 7y = 8](https://tex.z-dn.net/?f=7%2A2-7%2Ay%20%2B%207y%20%3D%208)
![14 -7y + 7y = 8](https://tex.z-dn.net/?f=14%20-7y%20%2B%207y%20%3D%208)
![14 \neq 8](https://tex.z-dn.net/?f=14%20%20%5Cneq%208)
At this point, we conclude that thee system has no solution.
----------------------------------------------
15)
--- 1
----2
Substitute
in (2)
![5x + 3x + 4 = -92](https://tex.z-dn.net/?f=5x%20%2B%203x%20%2B%204%20%3D%20-92)
![8x + 4 = -92](https://tex.z-dn.net/?f=8x%20%2B%204%20%3D%20-92)
Subtract 4 from both sides
![8x + 4 -4= -92 -4](https://tex.z-dn.net/?f=8x%20%2B%204%20-4%3D%20-92%20-4)
![8x = -96](https://tex.z-dn.net/?f=8x%20%3D%20-96)
Divide both sides by 8
![\frac{8x}{8} = \frac{-96}{8}](https://tex.z-dn.net/?f=%5Cfrac%7B8x%7D%7B8%7D%20%3D%20%5Cfrac%7B-96%7D%7B8%7D)
![x = -12](https://tex.z-dn.net/?f=x%20%3D%20-12)
Substitute
in equation 1
![y = 3x + 4](https://tex.z-dn.net/?f=y%20%3D%203x%20%2B%204)
![y = 3(-12) + 4](https://tex.z-dn.net/?f=y%20%3D%203%28-12%29%20%2B%204)
![y = -36 + 4](https://tex.z-dn.net/?f=y%20%3D%20-36%20%2B%204)
![y = -32](https://tex.z-dn.net/?f=y%20%3D%20-32)
![Hence\ (x,y) = (-12,-32)](https://tex.z-dn.net/?f=Hence%5C%20%28x%2Cy%29%20%3D%20%28-12%2C-32%29)
----------------------------------------------
16)
![0.4x + 0.4y = 4](https://tex.z-dn.net/?f=0.4x%20%2B%200.4y%20%3D%204)
![0.4x - 0.4y = 1](https://tex.z-dn.net/?f=0.4x%20-%200.4y%20%3D%201)
Add both equations
![(0.4x + 0.4y = 4) + (0.4x - 0.4y = 1)](https://tex.z-dn.net/?f=%280.4x%20%2B%200.4y%20%3D%204%29%20%2B%20%280.4x%20-%200.4y%20%3D%201%29)
![0.4x+0.4x + 0.4y-0.4y = 4+1](https://tex.z-dn.net/?f=0.4x%2B0.4x%20%2B%200.4y-0.4y%20%3D%204%2B1)
![0.8x = 5](https://tex.z-dn.net/?f=0.8x%20%3D%205)
Divide both sides by 0.8
![\frac{0.8x}{0.8} = \frac{5}{0.8}](https://tex.z-dn.net/?f=%5Cfrac%7B0.8x%7D%7B0.8%7D%20%3D%20%5Cfrac%7B5%7D%7B0.8%7D)
![x = 6.25](https://tex.z-dn.net/?f=x%20%3D%206.25)
Substitute
in (1)
![0.4(6.25) + 0.4y = 4](https://tex.z-dn.net/?f=0.4%286.25%29%20%2B%200.4y%20%3D%204)
![2.5 + 0.4y = 4](https://tex.z-dn.net/?f=2.5%20%2B%200.4y%20%3D%204)
Subtract 2.5 from both sides
![2.5 -2.5 + 0.4y = 4 -2.5](https://tex.z-dn.net/?f=2.5%20-2.5%20%2B%200.4y%20%3D%204%20-2.5)
![0.4y = 1.5](https://tex.z-dn.net/?f=0.4y%20%3D%201.5)
Divide both sides by 0.4
![\frac{0.4y}{0.4} = \frac{1.5}{0.4}](https://tex.z-dn.net/?f=%5Cfrac%7B0.4y%7D%7B0.4%7D%20%3D%20%5Cfrac%7B1.5%7D%7B0.4%7D)
![y = \frac{1.5}{0.4}](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7B1.5%7D%7B0.4%7D)
![y = 3.75](https://tex.z-dn.net/?f=y%20%3D%203.75)
![Hence,\ (x,y) = (3.75,6.25)](https://tex.z-dn.net/?f=Hence%2C%5C%20%28x%2Cy%29%20%3D%20%283.75%2C6.25%29)
----------------------------------------------
17)
![x - 4y = 1](https://tex.z-dn.net/?f=x%20-%204y%20%3D%201)
![x= 7+ 4y](https://tex.z-dn.net/?f=x%3D%207%2B%204y)
Substitute
in (1)
![7 + 4y - 4y = 1](https://tex.z-dn.net/?f=7%20%2B%204y%20-%204y%20%3D%201)
![7 \neq 1](https://tex.z-dn.net/?f=7%20%5Cneq%201)
At this point, we conclude that thee system has no solution.
Answer:
Population Education is the study of total number of people living in a particular place in acertain period of time .
Explanation:
Population is derived from French word "Populous " meaning people so population is study of people living together and education is life long knowledge
When they give us all this data and asks us to find the margin of error we can use the next formula
<span>margin of error = (0.745 - 0.707) / 2 = 0.019
There is your answer. I hope this helps you a lot</span>
<span>John Locke is to Immanuel Kant as "nurture" is to "nature".
JohnLocke and Immanuel Kant both were great philosophers, Kant's moral theory is famously known as defining the good act with recognition for the duties fulfilled by the person doing the act. John Locke is the founder of</span><span> British Empiricism</span><span> school of thought.</span>
Number three is C
Number four is B
Number five is D