Answer:
Growth function = 2nd
Decay function = 1st, 3rd, 4th, 5th
Explanation:
The general exponential function is

where, a is the initial value and b is growth or decay factor.
If 0<b<1, then it is a decay function and if b>1, then it is a growth function.
In function 1,

It can be rewritten as

Since b=0.5<1, therefore it is a decay function.
Similarly,
In function 2,

b=1.25>1, therefore it is a growth function.
In function 3,

b=0.97<1, therefore it is a decay function.
In function 4,

b=0.98<1, therefore it is a decay function.
In function 5,

b=0.5<1, therefore it is a decay function.
Therefore, only 2nd function is growth function and all other functions are decay function.