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.
The question is incomplete. The complete question is :
A man travels by a car from town A to town B, a total distance of 100 km at an average speed of x km/h. he finds that the time for the journey would be shorter by 25 minutes if he increases his average speed by 12km/h. Find x ?
Solution :
It is given the that the distance between town A and B is = 100 km
His initial average speed is = x km/h
His increased average speed is = 12 km/h
Time is shortened by = 25 minutes
So according to the question,


x-12 = 2500
x = 2512
Answer:
please send full question
Step-by-step explanation:
A triangle is a polygon with three edges and three vertices, perimeter of ΔABC = 36cm.
<h3>Congruent triangles are what?</h3>
Congruent triangles are two triangles that are identical in terms of their size and shape. One of two congruent triangles remains congruent even if it is rotated, flipped, or turned. Two triangles must have the same sides in order for them to have the same angles and, as a result, to be congruent.
Triangles with equal measures are congruent.
36cm = perimeter of ΔABC
Here we have,
ΔABC ≅ Δ XYZ
So,

Therefore, perimeter of ΔABC = 36cm
To know more about Congruent triangles visit:
brainly.com/question/22062407
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