Answer:
A solution to a system of equations means the point must work in both equations in the system. So, we test the point in both equations. It must be a solution for both to be a solution to the system. Hope this helps.
The answer is B. The values of y must only be positive because it is equal to

The other options states that the values of y could be negative which is why it is wrong.
Answer:
Step-by-step explanation:
P1 = (2000, 1000) in the form (x1,y1)
P2 = (2012, 3400) in the form (x2,y2)
m = (y2-y1 / x2-x1)
m = ( 3400-1000 ) / (2012 - 2000)
m = 2400 / 12
m = 200
y = 200x + 800
X=2
subtract 5x on both sides
-2x=-4
divide by -1 on both sides
2x=4
divide by 2 on both sides
x= 2