Answer:
x=34
Step-by-step explanation:

D
The cable increases by 20 in addition to the length of cable needed
Explicit rule is a(n) = 9*(-5)^(n-1)
The recursive rule is a(n) = -5*a(n-1); a(1) = 9
The first term is 9. Each new term is found by multiplying the previous term by -5
We can see this when we raise -5 to a whole number power. Eg: 9(-5)^3 = 9*(-5)*(-5)*(-5)
Answer: Choice D