Answer:
(2,-5)
Step-by-step explanation:
A constant is any number, anywhere on the number line.
A variable is an unknown, x y z n etc
The general formula for exponential growth and decays is:

if k>0 then then it is an exponential growth function. If k<0 then the function represents an exponential decay.
Now we need to classify each of the functions:
1.
The function

can be wrtten as:

comparing with the general formula we notice that k=2, therefore this is an exponential growth.
2.
The function

can be written as:

comparing with the general formula we notice that k=-4, therefore this is an exponential decay.
3.
The function

comparing with the general formula we notice that k=-1, therefore this is an exponential decay.
.0000000083
( eight zeros.)
All in all you would get the answer x+y=1.