The answer is 200 points. Because when you add this 200 to her first 200 points, you will get her final points which is 400 points. Hope I was able to help.
Answer: The amount of salt in the tank after 8 minutes is 36.52 pounds.
Step-by-step explanation:
Salt in the tank is modelled by the Principle of Mass Conservation, which states:
(Salt mass rate per unit time to the tank) - (Salt mass per unit time from the tank) = (Salt accumulation rate of the tank)
Flow is measured as the product of salt concentration and flow. A well stirred mixture means that salt concentrations within tank and in the output mass flow are the same. Inflow salt concentration remains constant. Hence:

By expanding the previous equation:

The tank capacity and capacity rate of change given in gallons and gallons per minute are, respectivelly:

Since there is no accumulation within the tank, expression is simplified to this:

By rearranging the expression, it is noticed the presence of a First-Order Non-Homogeneous Linear Ordinary Differential Equation:
, where
.

The solution of this equation is:

The salt concentration after 8 minutes is:

The instantaneous amount of salt in the tank is:
Step-by-step explanation:
In words it is: The product of -11 and k is 22.
The solution is: -11 = +11
22+11 = 33
33 = k
Answer: I: (3, +infinity) D: (-infinity, 3) (this is the fourth answer)
Step-by-step explanation: The graph is decreasing left to right until 3, and begins to increase from left to right beginning at 3.
The area is 84.
What I do it cut the polygon into something easier like a square and rectangle.
Rectangle: 6•12=72
Square: 4•3=12
Add them together and you have 84