Answer: 
Step-by-step explanation:
There are 400 balcony seats in the concert hall.
<u>Step-by-step explanation</u>:
Step 1 :
- The number of lower seats = 450 seats
Total seats = Lower seats + balcony seats
Step 2 :
- Tickets sold = 170 tickets
- Total tickets = x
Tickets sold = 1/5 of total tickets.
⇒ 170 = (1/5)x
⇒ x = 5
170
⇒ x = 850 tickets
∴ Total seats in the concert hall is 850.
Step 3 :
Total seats = 450 + balcony seats
850 - 450 = balcony seats
∴ balcony seats = 400
Answer: Level of the liquid dropping at 28.28 inch/second when the liquid is 2 inches deep.
Step-by-step explanation:
Since we have given that
Height = 9 inches
Diameter = 6 inches
Radius = 3 inches
So, 
Volume of cone is given by

By differentiating with respect to time t, we get that

Now, the liquid drips out the bottom of the filter at the constant rate of 4 cubic inches per second, ie 
and h = 2 inches deep.

Hence, level of the liquid dropping at 28.28 inch/second when the liquid is 2 inches deep.
Answer:
x = - 3
Step-by-step explanation:
Given
7(x + 2) = 2x - 1 ← distribute parenthesis on left side
7x + 14 = 2x - 1 ( subtract 2x from both sides )
5x + 14 = - 1 ( subtract 14 from both sides )
5x = - 15 ( divide both sides by 5 )
x = - 3
Answer:
Step-by-step explanation: