I really need this answer right away. Im taking an exam. How long has the polygraph machine been in use?
A.Over 2000 years
B. Over 1000 years
C.Over 200 years
D. Over 100 years

All the time.

Step-by-step explanation:

Here,

x= elapsed time

y = number of gallons of water in tank.

For tank A,

3y=750x+300

Divide both sides by 3, we get

y= 250x+100 ...(i)

For tank B,

4y=1000x+400

Divide both sides by 4, we get

y=250+100 ...(ii)

From (i) and (ii) it can be seen that both the function are same.

That means the amount of watre will be same for every value of x, where x ≥0