I believe the answer should be 270.
You should replace the “d” in 30d with a nine because the “d” stands for how many days. The question said there are nine days so you would get this...
30x9=270 minutes in total
You can solve a system of equations 3 ways.
1. Elimination
This method is eliminates one of the variables in the system of equations to get 1 equation with only one 1 variable.
2. Graph
You graph both of the equations and find where they intersect if at all.
3. Substitution
If you know the value of one of variables, you can substitute it back into the equation.
Answer:
1836 bacteria
Step-by-step explanation:
Now the data is a progression; 38,000, 33,820, 30,100 .........
We can find out what type of progression it is, in this case, we can see that it is a geometric progression because;
r= 33,820/38,000 = 30,100/33,820 = 0.89
So, for a geometric progression;
Un = ar^n-1
Where;
a = 38,000
r = 0.89
n = 27 days
Un = ???
Un = 38,000 * (0.89)^27 - 1
Un = 1836 bacteria
The result is number 
where:
Hope this helps.
Any number greater than 9
