we know that
f(3) is the value of the function when x is equal to 3
so
For x=3
see in the graph
f(3)=6
see the attached figure
therefore
<u>the answer is</u>
f(3)=6
Answer:

Step-by-step explanation:
Commission received on selling each storm window
of the selling price of each storm window
Commission received on selling each door
of the selling price of each door
Amount earned on selling storm windows = $5,400
Amount earned on selling doors = $28,790
Commission received on selling storm windows 
Commission received on selling doors 
Therefore,
Total commission received 
I’ll help, but it is difficult to see the terms on the paper!
PART 1.
Going westward:
Distance: 2400 miles
Rate (this is speed): (450-wind_speed) mph
Time: distance / speed = 2400 / (450-wind speed)
Going eastward:
Distance: 2400 miles
Rate (this is speed): (450+wind_speed) mph
Time: distance / speed = 2400 / (450+wind speed)
PART 2
Formula for speed:
speed = distance / time
Now we solve this for time:
time = distance / speed
11h = 2400 / (450+-wind_speed)
+- sign is put because in one case wind increases speed of plane and in other case it decreases speed.
PART 3
To solve for wind_speed we start by rearranging formula so that we have wind_speed on left side:
(450+-wind_speed) = 2400 / 11
(450+-wind_speed) = 218mph
To fly this distance in 11h speed of plane must be 218mph.
The only way to get this solution is if we substract wind speed:
450-wind_speed = 218
wind_speed = 450-218 = 232mph