= x·[2(x²- 4x + 4) + 3(x² + 6x + 9) - x² + 5x]
= x(2x² - 8x + 8 + 3x² + 18x + 27 - x² + 5x)
= x(4x² + 15x + 35)
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