To find the average rate of change, evaluate the function at the given points.
Evaluate the difference of the function at the given points.
Divide the difference of the function at the given points with the difference of the given points.
" 100% " means "the whole thing",
and "is" can be replaced by "is equal to".
You have said "The whole thing of a number is equal to 61."
or
"61 is equal to the whole thing of a number."
The only number that 61 can be equal to is 61.
The answer is -10 because when u plug in -2 for x u get 4(-2)=-8 then -2+-8=-10