Answer:
Step-by-step explanation:
Given that a large mixing tank initially holds 400 gallons of water in which 70 pounds of salt have been dissolved. Pure water is pumped into the tank at a rate of 4 gal/min, and when the solution is well stirred, it is then pumped out at the same rate.
Let Q(t) be the quantity of salt at time t.
Q(0) = 70 pounds
Inflow of water = outflow = 4 gal/min
So resulting volume of tank at time t = 400 gallons
Rate of change of salt = inflow - outflow
= 0 - 
i.e. 
This is a variable separable equation
Use when t =0 Q = 70
A =70
So A(t) = Q(t) = 
and
A(0) = Q(0) = 70 lbs.
Answer:
B
Step-by-step explanation:
cus thats the formula
Resolviendo un sistema de ecuaciones, veremos que se vendieron 250 boletos de adulto.
<h3>¿Cuántos boletos de adulto fueron vendidos?</h3>
Definamos las variables:
- x = boletos de adulto vendidos.
- y = boletos de estudiantes vendidos.
Se vendieron un total de 430 boletos, entonces:
x + y = 430
Y se vendieron 70 boletos de estudiante menos que boletos de adulto:
y = x - 70
Tenemos el sistema de ecuaciones:
x + y = 430
y = x - 70
Para resolverlo, podemos reemplazar la segunda ecuación en la primera:
x + y = 430
x + (x - 70) = 430
2x = 430 + 70 = 500
x = 500/2 = 250
Se vendieron 250 boletos de adulto.
Sí quieres aprender más sobre sistemas de ecuaciones:
brainly.com/question/13729904
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