Answer:
Rate of Change = 7
Explanation:
The rate of change given is simply asking you to find the slope of the given values.
Interpreting your x=0 you have the value of 32 as you Y-intercept.
Now that you see when x=1 you have the value of 39.
When subtracted from one another you get:
39 - 32 = 7
This would mean the value of X is 7 -> This is the rate of change!
If you want more proof that it is 7, here it is!
Plug in x=7 for 3x you get 14 + 39 = 53
Plug in x=7 for 6x you get 21 + 53 = 74