Salt flows in at a rate of (5 g/L)*(3 L/min) = 15 g/min.
Salt flows out at a rate of (x/10 g/L)*(3 L/min) = 3x/10 g/min.
So the net flow rate of salt, given by 
in grams, is governed by the differential equation,
which is linear. Move the 
term to the right side, then multiply both sides by 
:
Integrate both sides, then solve for :
Since the tank starts with 5 g of salt at time 
, we have
The time it takes for the tank to hold 20 g of salt is 
such that
Answer:
The first, second to last and last stements are true
Step-by-step explanation:
You times 8 by the percentage as
e.g 8 x 1.50 = 12 is the same as marked up by 50%
e.g 8 x 1.70 =13.6 is the same as marked up by 70%
Answer How many liters of a 20% acid solution should be mixed with 30 liters of 50% acid solution in order to obtain a 40% solution. ... x=15 liters 15*(.20 pure acid)=3 liters 30*(.50 pure acid)=15 liters That is 18 liters pure acid That is 45 liters solution *0.45 pure acid=18 liters.
As more pure acid is added, the concentration of acid approaches 0.
AB is divided into 8 equal parts and point C is 1 part FROM A TO B, so the ratio is 1:7, with C being 1/7 of the way. The ratio is k, found by writing the numerator of the ratio (1) over the sum of the numerator and denominator (1+7). So our k value is 1/8. Now we need to find the rise and the run (slope) of the points A and B.
. That gives us a rise of -4 and a run of 12. The coordinates of C are found in this formula:
![C(x,y)=[ x_{1} +k(run), y_{1} +k(rise)]](https://tex.z-dn.net/?f=C%28x%2Cy%29%3D%5B%20x_%7B1%7D%20%2Bk%28run%29%2C%20y_%7B1%7D%20%2Bk%28rise%29%5D)
. Filling in accordingly, we have
![C(x,y)=[-3+ \frac{1}{8}(12),9+ \frac{1}{8}(-4)]](https://tex.z-dn.net/?f=C%28x%2Cy%29%3D%5B-3%2B%20%5Cfrac%7B1%7D%7B8%7D%2812%29%2C9%2B%20%5Cfrac%7B1%7D%7B8%7D%28-4%29%5D%20%20)
which simplifies a bit to
. Finding common denominators and doing the math gives us that the coordinates of point C are
. There you go!
