for the function f(x)=7/x+6, find the average rate of change of f from 1 to x.

Answer 1

f(x) - f(1)
------------
x-1

7/(x+6) - 1
-------------
x-1

7 - (x+6)
-----------
(x-1)(x+6)

1-x
--------------
(x-1)(x+6)

-1/(x+6)