Answer:
AA
Step-by-step explanation:
Yes. 3/2 is equivalent to 1.5
Answer:
Step-by-step explanation:
concentration = amount of salt/solution
A) Initial concentration= 90/1000 = 0.09
Q = quantity of salt
Q(0) = 90 kg
Inflow rate = 8 l/min
Outflow rate = 8 l/min
Solution = 1000 L at any time t.
Salt inflow = 0.045 * 8 per minute
= 0.36 kg per minute
This is mixed and drains from the tank.
Outflow = 
Thus rate of change of salt
Q'(t) = inflow - outflow = 
Separate the variables and integrate

Use the fact that Q(0) = 90
90 = 360-A
A = 270
So

B) Q(t) = 360-270e^-0.004 = 91.07784
C) When t approaches infinity, we get
Q(t) tends to 360
So concentration =360/1000 = 0.36
Answer:
SA = 16x^2 +30x+6
Step-by-step explanation:
The surface area is given by
SA = 2 (lw + lh + wh)
The length is 2x, the width is (x+3) and the height is (2x+1)
SA = 2 ((2x)*(x+3) + (2x)*(2x+1) + (x+3) (2x+1))
We need to distribute
SA = 2 ((2x^2+6x) + (4x^2+2x) + (2x^2 +6x+x+3))
Combine like terms
SA = 2 (2x^2+ 4x^2+2x^2+6x+2x +6x+x+3)
SA = 2 (8x^2+15x+3)
Multiply by 2
SA = 16x^2 +30x+6