The answer is c or the third option. If we start at one we get (4(1)-9)=-5, then we can do 2 and we get (4(2)-9)=-1. Lets do 3 (4(3)-9)=3. Now 4 (4(4)-9)=7. Now 5 and our last one (4(5)-9)=11. Now notice we get -5+-1+3+7+11.
9 + 5 + 4 + 7 = 25
Ratio = 5 : 25
Ratio = 1 : 5 <==== answer
Exponential functions are related to logarithmic functions in that they are inverse functions. Exponential functions move quickly up towards a [y] infinity, bounded by a vertical asymptote (aka limit), whereas logarithmic functions start quick but then taper out towards an [x] infinity, bounded by a horizontal asymptote (aka limit).
If we use the natural logarithm (ln) as an example, the constant "e" is the base of ln, such that:
ln(x) = y, which is really stating that the base (assumed "e" even though not shown), that:

if we try to solve for y in this form it's nearly impossible, that's why we stick with ln(x) = y
but to find the inverse of the form:

switch the x and y, then solve for y:

So the exponential function is the inverse of the logarithmic one, f(x) = ln x
C
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