Answer:
dy/dt = 7y / (t − 1000)
Step-by-step explanation:
Change in mass of salt = mass of salt going in − mass of salt going out
dy/dt = 0 − (C kg/L × 7 L/min)
where C is the concentration of salt in the tank.
The concentration is mass divided by volume:
C = y / V
The volume in the tank as a function of time is:
V = 1000 + 6t − 7t
V = 1000 − t
Therefore:
C = y / (1000 − t)
Substituting:
dy/dt = -7y / (1000 − t)
dy/dt = 7y / (t − 1000)
If we wanted, we could separate the variables and integrate. But the problem only asks that we find the differential equation, so here's the answer.
Answer:
188000
Step-by-step explanation:
V≈1.88×
Answer:
1/12
Step-by-step explanation:
you need to make sure that they have a common denominator before doing anything.
Find the lowest common multiple (lcm), which would be 12 (3 x 4 = 12)
So then, put 12 as both denominators, and subtract.
7/12 - 9/12 is equal to 28/12 - 27/12, because 3 miltiplied by 4 equals 12, therefore you mutiply the 7 by the 4, and 4 miltiplied by 3 equals 12, therefore you multiply the 9 by the 3.
Sorry if this is confusing, i tried explaining as best i could! Hope this helped!
Answer:
$156.25
Step-by-step explanation:
A good strategy in my opinion is the "finders" strategy
50$ = 32%
x = 100%
First Multiply 100 by 50
100 x 50 = 5,000
Then Divide 5,000 with 32
5,000/32 = $156.25
If you want to check, then...
156.25 x 32 = 5,000
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<em>x = $156.25</em>
Hope this helps!
-Greg
