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
Answer: A translation 5 units to the left... brainliest?
Step-by-step explanation: edge 2020
Use substitution and substitute y into the other equation. One of the equations already gives you y in terms of x, so use that and substitute it into the other equation. y = 3x - 4
Plug into the other equation: -3y = -9x + 12
-3(3x-4) = -9x + 12
-9x + 12 = -9x + 12
This is an identity. So that means that any value of x makes this equation true. So B.
Answer:
d(10)=20?
Step-by-step explanation:
Hope it helps
can i have the crown(brainliest)?
Answer:
x = 4
Step-by-step explanation:
The base angles of an isosceles triangle are congruent, as shown in the figure.
Equating their measures, we have ...
∠A = ∠C
8x -7 = 25 . . . . substitute the given expressions
8x = 32 . . . . . add 7
x = 4 . . . . . . divide by 8