Answer:
The answer is B.
Step-by-step explanation:
When Elimination method is applied, you have to eliminate one of the variables from both equations. Firstly, both equations contain 4y so you can subtract it :
![7x + 4y = 39 - - - (1)](https://tex.z-dn.net/?f=7x%20%2B%204y%20%3D%2039%20-%20%20-%20%20-%20%281%29)
![2x + 4y = 14 - - - (2)](https://tex.z-dn.net/?f=2x%20%2B%204y%20%3D%2014%20-%20%20-%20%20-%20%282%29)
![(1) - (2)](https://tex.z-dn.net/?f=%281%29%20-%20%282%29)
![7x + 4y - 2x - 4y = 39 - 14](https://tex.z-dn.net/?f=7x%20%2B%204y%20-%202x%20-%204y%20%3D%2039%20-%2014)
![5x = 25](https://tex.z-dn.net/?f=5x%20%3D%2025)
![x = 25 \div 5](https://tex.z-dn.net/?f=x%20%3D%2025%20%5Cdiv%205)
![x = 5](https://tex.z-dn.net/?f=x%20%3D%205)
Next, you have to substitute x = 5 to any equations. I will choose to put in (2) :
![substitute \: x = 5 \: into \: (2)](https://tex.z-dn.net/?f=substitute%20%5C%3A%20x%20%3D%205%20%5C%3A%20into%20%5C%3A%20%282%29)
![2(5) + 4y = 14](https://tex.z-dn.net/?f=2%285%29%20%2B%204y%20%3D%2014)
![10 + 4y = 14](https://tex.z-dn.net/?f=10%20%2B%204y%20%3D%2014)
![4y = 14 - 10](https://tex.z-dn.net/?f=4y%20%3D%2014%20-%2010)
![4y = 4](https://tex.z-dn.net/?f=4y%20%3D%204)
![y = 4 \div 4](https://tex.z-dn.net/?f=y%20%3D%204%20%5Cdiv%204)
![y = 1](https://tex.z-dn.net/?f=y%20%3D%201)
Therefore, put your answer in coordinate form :
![x = 5 \\ y = 1](https://tex.z-dn.net/?f=x%20%3D%205%20%5C%5C%20y%20%3D%201)
![(5,1)](https://tex.z-dn.net/?f=%285%2C1%29)
Basically just read this and you will understand it better
Answer:
# = -2
Step-by-step explanation:
3 x # = -6
3 / -6 = -2
# = -2
Input 15 as the initial value and (3, 90) as x and y to get the equation 90=m(3)+15. Isolate m to get m=25. Each shirt costs $25 and the equation that represents the scenario is y=25x+15.
Hello here is a solution :