John is correct because 0.5 is equal to one half and multiplying something by its half is just same as dividing something in two and half of 1.4 is 0.5
(sorry if it's too long feel free to shorten it)
Answer: 
Step-by-step explanation:

Add
on both sides and subtract
on both sides to leave x's on the left side and independent values on the right.


Solve the fractions.





Convert the mixed fraction
to an improper fraction. You can do this by multiplying 1 times 35 and adding 2.

Now use the reciprocal (inverse fraction) and multiply on both sides to isolate x.




First of all, a positive average rate of change means that the function is increasing, so the answer can only be A->B or B->C.
The average rate of change is defined as

i.e. as the ratio between the vertical and horizontal gain.
In order to go from point A to point B, you gain 1 unit horizontally and 5 units vertically. So, the average rate of change is 5/1=5.
In order to go from point B to point C, you gain 1 unit horizontally and 3 units vertically. So, the average rate of change is 3/1=3.
Answer: for 9 attendees it would cost $18
Step-by-step explanation: First you have to find the unit rate. So for every 7 attendees it costs $14, divide them both by the GCF which is 7. 14÷7=2
7÷7=1
So for every 1 attendee it is $2.
Now to figure out how much it would cost for 9 attendees, figure out what you have to do to 1 to get 9. Multiply it by 9.
And whatever you do to one number you have to do for the other. So $2 • 9 = $18
So for every 9 attendees it costs $18.