1) 9x + 2 = x + 5 ---> 9x + 2 = 6
subtracted X from one side but not the other
2) 3(x-4) + 5 = 12 ---> 3x + 4 + 5 = 12
didn't distribute correctly: 3(x-4)
multiplied the X by 3 but not the -4
It would take about 57 hours for the number of spores to be less than 500 spores.
<h3>
Exponential Function</h3>
An exponential function is in the form:
y = abˣ
Where y,x are variables, a is the initial value of y and b is the multiplication factor.
Let y is the number of pores after x hours.
a = 6200, b = 100% - 20% = 0.8, hence to be less than 500 spores:

(x/5) * ln(0.8) < ln(0.08)
x > 56.4 hours
It would take about 57 hours for the number of spores to be less than 500 spores.
Find out more on Exponential Function at: brainly.com/question/12940982
Answer:
D
Step-by-step explanation: