Answer:
Step-by-step explanation:
This is a differential equation problem most easily solved with an exponential decay equation of the form
. We know that the initial amount of salt in the tank is 28 pounds, so
C = 28. Now we just need to find k.
The concentration of salt changes as the pure water flows in and the salt water flows out. So the change in concentration, where y is the concentration of salt in the tank, is
. Thus, the change in the concentration of salt is found in
inflow of salt - outflow of salt
Pure water, what is flowing into the tank, has no salt in it at all; and since we don't know how much salt is leaving (our unknown, basically), the outflow at 3 gal/min is 3 times the amount of salt leaving out of the 400 gallons of salt water at time t:

Therefore,
or just
and in terms of time,

Thus, our equation is
and filling in 16 for the number of minutes in t:
y = 24.834 pounds of salt
Circumference = 2 x radius x Pi
Circumference = 2 x 0.8 x pi
Circumference = 1.6pi or 5.024 yards
area = r^2 x pi
Area = 0.8^2 x pi
Area = 0.64pi or 2.0096 square yards
Answer:
for number 6 the answer is 6x = -12
the value of x would be 2
Answer:
-2.22, -√3, √9, π, 3.4
Step-by-step explanation:
Hope this helps :)