Let's take the number as x.
two-fifths of a number = 2x / 5
decreased by 3 = (2x/5) - 3
(2x/5) - 3
(2*25/5) - 3
(2*5) - 3
10 - 3
7
Set up a differential equation using rate of salt going in minus rate going out.
Rate = dS/dt = salt/gal* gal/min
Also the number of gallons in tank is increasing at (4-2) gal/min = 2 gal/min
The volume of tank at any given time = 100+2t
Differential Equation:

Use integrating factor of t+50
![[S(t+50)]' = t+50](https://tex.z-dn.net/?f=%5BS%28t%2B50%29%5D%27%20%3D%20t%2B50)
Integrate both sides

Solve for constant c given S(0) = 20
c = 1000
Tank is full at 200 gallons when t =50
100+2t = 200 ---> t = 50
S(50) = 47.5
Final Answer: There are 47.5 pounds of salt
Answer:
Slope
Step-by-step explanation:
Slope is the 'steepness' of the line, also commonly known as rise over run. We can calculate slope by dividing the change in the y-value between two points over the change in the x-value.
Answer:
Step-by-step explanation:
2x - 5
2(3) - 5
2 times 3 = 6
6-5=1
B) is the answer