Answer:
51.3
Step-by-step explanation:
I will upload a photo soon, but it is from trig, and inverse cos.
Answer: the speed of the current is 9 mph.
Step-by-step explanation:
Let x represent the speed of the current.
A boat can travel 21 mph in still water. If it travels 270 miles with the current. It means that the total speed with which the boat travelled with the current is (21 + x) mph.
Time = distance/speed
Time spent by the boat in travelling 270 miles is
270/(21 + x)
In the same length of time, it travels 108 miles against the current. It means that the total speed with which the boat travelled against the current is (21 - x) mph.
Time = distance/speed
Time spent by the boat in travelling 108 miles is
108/(21 - x)
Since the time is the same, then
270/(21 + x) = 108/(21 - x)
270(21 - x) = 108(21 + x)
5670 - 270x = 2268 - 108x
108x + 270x = 5670 - 2268
378x = 3402
x = 3402/378
x = 9
Answer: -3/2x + 3 ⠀⠀⠀⠀⠀⠀ ⠀⠀⠀⠀⠀⠀
D is a function because there are no repeated x values
for example b is not a function because we have (0,-7) and (0,-9)
Answer:
-2.5x-.5

draw the dotted line (3/7)x-3 and shade below it
Step-by-step explanation:
First, we need the slope
Use the slope formula:

so we have
y= -2.5x+b
Solve for b by plugging in coordiantes
-8= -2.5(3)+b
-8= -7.5+b
b= -.5
Put it together and get -2.5x-.5
2.)
A line is parallel to another line if they have the same slope (and different y intercepts)
So in the formula y=mx+b we knowe that m= 2/3
Now it's just a matter of solving for B
plug in the required coordinate to do this
-1=(2/3)*0+b
-1= b
Put it all together to get

3.)
put this into slope intercept form
3x-7y>21
3x-21 > 7y
(3/7)x-3 >y
To graph this just draw a dotted line with the equation (3/7)x-3 and shade everything below it (use de_smos if you're stuck)