Initially, a large tank with a capacity of 100 gallons contains 50 gallons of pure water. A salt solution with concentration of 0.1 lb/gal flows into the tank at a rate of 2 gal/min. The mixture is well stirred and flows out of the tank at the rate of 4 gal/min. Find the initial-value problem that describes the amount of salt in the tank until the tank is empty.

exa:

)

3+11

14

step-by-step explanation:

from this example, we can see that subtracting with integers is the same as adding the opposite. we can solve using a number line or by using the saying "keep, change, change" to us solve. it is important to remember that we can subtract a negative and end up with a larger number than we started with.

what i would say the best answer is a. 40.5