Answer: Solution
=
−
6
Step-by-step explanation:
A=pi radius^2
7 is the radius
Pi7^2=153.93
Answer:
100/100
Step-by-step explanation:
Answer:
x = 3 ± i 
Step-by-step explanation:
Given
x² - 6x + 12 = 0 ( subtract 12 from both sides )
x² - 6x = - 12
Using the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 3)x + 9 = - 12 + 9
(x - 3)² = - 3 ( take the square root of both sides )
x - 3 = ± 
= ± i ( add 3 to both sides )
x = 3 ± i
9514 1404 393
Answer:
Step-by-step explanation:
The speed against the wind is ...
4680 mi/(8 h) = 585 mi/h
The speed with the wind is ...
5720 mi/(8 h) = 715 mi/h
The speed of the airplane in still air is the average of these speeds:
(585 +715)/2 = 650 mi/h . . . speed in still air
The speed of the wind is the difference between the airplane speed and the speed in the wind:
715 -650 = 65 mi/h . . . speed of the wind
_____
<em>Additional comment</em>
If p and 'a' represent the speeds of the plane and the air, the speeds with and against the wind are ...
p + a = with
p - a = against
If we average these, we get ...
((p +a) +(p -a))/2 = (with + against)/2
p = (with + against)/2 . . . . . . . the formula we used above
