Answer:
a) 
b) 
Step-by-step explanation:
By definition, we have that the change rate of salt in the tank is
, where
is the rate of salt entering and
is the rate of salt going outside.
Then we have,
, and

So we obtain.
, then
, and using the integrating factor
, therefore
, we get
, after integrating both sides
, therefore
, to find
we know that the tank initially contains a salt concentration of 10 g/L, that means the initial conditions
, so 

Finally we can write an expression for the amount of salt in the tank at any time t, it is 
b) The tank will overflow due Rin>Rout, at a rate of
, due we have 500 L to overflow
, so we can evualuate the expression of a)
, is the salt concentration when the tank overflows
I think it D cause 30(cos(30x)+14=-16
Your dividing by 30
your 180 (which is degrees) is
radians. As the cosine function is periodic with period 2 we get
Answer:
Step-by-step explanation:
25b * (3a² - 1) = 25b * 3a² - 25b * 1
= 75ba² - 25b
Distributive law upon subtraction:
a(x - y) = ax - ay
Answer:
Valid Argument
Step-by-step explanation:
An argument is valid if its conclusion follows with certainty from its premises.
Given:
Premise: If it has an engine, I can fix it.
Premise: Cars have engines.
Conclusion: I can fix cars.
The argument is valid since the conclusion follows with certainty from the given premises.