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
I think it’s C i think is right
Answer:
x = 14.2 y=15.
Step-by-step explanation:
Answer:
C) 125°
Step-by-step explanation:
Supplementary angles add to 180 degrees. Complementary angles add to 90
An angle's complement is 35°.
35+x =90
Subtract 35 from each side
35 -35+x = 90-35
x = 55
We want to find the supplement of this angle
55+y = 180
Subtract 55 from each side
55-55+y = 180-55
y= 125
The angle is 55 so its supplement is 125
Answer:
{x,y} = {115/17,-23/17}
Step-by-step explanation:
I believe its true.