A circular pool with a diameter of 18 ft will have a uniform
4 ft concrete walkway poured around it. If the concrete cost $4.25 a square
foot, how much will it cost for the concrete?
This can be solve be solving the area of walkway
Area of walkway is equal to = (pi)( 9 ft +4) ^2– (pi)(9ft)^2
= 276.46 sq ft
Cost = 276.46 sq ft * ($4.25 a square foot) = $1174.70
Answer:
x = 387
Step-by-step explanation:
The wind acts in the opposite direction to the plane when the time is longer.
The wind acts in the same direction as the plane when the time is shorter.
Equation
d = r*t
Givens
- d = 1720
- x = plane's speed
- y = wind speed
- t1 = 5 hours
- t2 = 4 hours.
Substitution
- d = (x + y) * t
- 1720 = (x + y) * 4
- 1720 = (x - y) * 5
Since the two distances are the same, you can equate the right hand sides.
- (x + y) * 4 = (x - y)*5 Remove the brackets.
- 4x + 4y = 5x - 5y Add 5y to both sides
- 4x + 4y + 5y = 5x - 5y + 5y Combine all the terms.
- 4x + 9y = 5x Subtract 4x from both sides
- 9y + 4x - 4x = 5x - 4x Combine
- 9y = x
Now use one of the given equations with the distance
- 1720 = (x + y)*4 Substitute 9y for x
- 1720 = (9y + y) * 4 Combine
- 1720 = 10y * 4 Multiply the right
- 1720 = 40y Divide by 40
- 1720/40 = 40y/40 Do the division
- 43 = y y = wind speek
- 9y = x x = 9*y
- 9*43 = x
- x = 387 miles per hour.
Answer
The answer would be 58
Step-by-step explanation:
3 to the power of 2 is 9
7 to the power of 2 is 49
add that you get 58
