Let <em>a</em> denote the airplane's speed in still air, and <em>w</em> the windspeed.
When the plane flies against the wind, it can travel an average speed of
(4500 km) / (6 h) = 750 km/h
so that
<em>a</em> - <em>w</em> = 750 km/h
Flying with the wind, it moves at a speed of
(2910 km) / (3 h) = 970 km/h
so that
<em>a</em> + <em>w</em> = 970 km/h
Add the two equations to eliminate <em>w</em> and solve for <em>a</em> :
(<em>a</em> - <em>w</em>) + (<em>a</em> + <em>w</em>) = 750 km/h + 970 km/h
2<em>a</em> = 1720 km/h
<em>a</em> = 860 km/h
Subtract them to eliminate <em>a</em> and solve for <em>w</em> :
(<em>a</em> - <em>w</em>) - (<em>a</em> + <em>w</em>) = 750 km/h - 970 km/h
-2<em>w</em> = -220 km/h
<em>w</em> = 110 km/h
Step-by-step explanation:
so first you combine like terms , 3x-x-4=4 turns into 4x-4=4 then u add 4 to both sides [inverse operations]
4x-4=4
+4 +4
--------------
4x= 8
----------
4. 4
×=2
then u use inverse operations. agian and divide 4 into 8 and you get 2 !! x = 2
Answer:
n^2+8n+16
Step-by-step explanation:
(n+4)^2
=(n+4) (n+4)
= n^2+4n+4n+16
=n^2+8n+16
Answer:
The answer is B.
Step-by-step explanation:
B and C (I think they are the same)
