Since, population of species A is represented by : 
Let us find the population of species A, at the end of week 1:
i.e., x = 1
i.e., 
i.e., 
i.e., 
Also, since population of species B is represented by : 
Let us find the population of species B, at the end of week 1:
i.e., x = 1
i.e., 
i.e., 
i.e., 
Thus, at the end of 1 week, species A and species B will have the same population.
Hence, option D is correct.
Let's use the slope-intercept equation:

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d)
It should take about 13.3 hours
Let x represent the number.
"three times a number" is 3x
eight less than "three times a number" is 3x-8
"is more than 22" is "> 22"
Your inequality is
3x-8 > 22