Answer:
A general exponential function is written as:
f(x) = A*e^(k*x)
Where A and k are real numbers.
Because we want to "create" a exponential function, we must assign numbers to A and k, let's assign:
A = 1
k = 1
then our function is just:
f(x) = e^(x)
Now we want to shift down 7 units.
So let's describe a general vertical shift.
For a general function f(x), a vertical shift is written as:
g(x) = f(x) + N
if N is positive, the shift is upwards
if N is negative, the shift is downwards.
Here we want to have a shift down of 7 units, then we would write:
g(x) = f(x) - 7
Replacing by the actual function f(x) we get:
g(x) = e^x - 7
Below you can see the graphs of both functions:
Where the orange one is f(x) and the purple one is g(x).