Answer:
All
Step-by-step explanation:
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:
128 servings can be made using 1 gallon of milk.
Step-by-step explanation:
Given that:
cups of milk make 10 servings
can also be written as 1.25
Ratio of cups of milk to servings = 1.25 : 10
1 gallon = 16 cups
Let,
x be the number of servings made from 1 gallon
Ratio of cups of milk to servings = 16 : x
This is a direct proportion
1.25 : 10 :: 16 : x
Product of mean = Product of extreme
10*16 = 1.25x
160 = 1.25x
1.25x=160
Dividing both sides by 1.25

Hence,
128 servings can be made using 1 gallon of milk.
Answer:
X = 8, Y = 8
Step-by-step explanation:
Step 1) Solve for Y w/ bottom equation to yield - y = -2/3x + 40/3.
Step 2) substitute equation into x + y = 16 to get 1/3x + 40/3 = 16 multiply by 3 to clear the fractions and get x + 40 = 48 - subtract 40 by both sides to get x = 8.
Step 3) Plug x = 8 into the bottom equation to get 48 + 9y = 120, subtract 48 by both sides to get 9y = 72 and then divide by 9. The product is y = 8.
4- distributive property
Reason
X(y+u)= xy+xu
Expansion is distributive property
Hope it helps